101 - Prophylaxis and treatment of whooping cough with a pertussis antigen

This was an unusual study on a vaccine-like method of protecting children from whooping cough. Instead of using whole killed bacterial cells, they grew the cells and filtered them out, leaving only soluble factors the bacteria had produced externally, which they called "antigen." Then they inactivated this antigen so it wouldn't cause any problems but would still induce an immune response, treating it with formaldehyde and mild heat. This was sorta like how tetanus and diphtheria toxoid vaccines were produced.

Then they tested this antigen for how well it could a) treat whooping cough cases, b) prevent catching the disease when given when not at risk, and c) prevent catching the disease when given after being exposed.

Antigen Therapy
They had two main groups: children with whooping cough treated with antigen, and control children with whooping cough. The controls were treated with either vaccine or vaccine + antigen. They don't specify what they mean by "vaccine;" details are pretty sparse in general.

The average time before each group was similar, about 1.5 weeks, but the duration of disease after treatment was about 1.6 weeks for the antigen-treated and 3 weeks for controls, so a pretty big difference.

The number of complications in the groups was different too: About 0.7% of the antigen-treated had complications from the disease (bronchitis, conjunctival hemorrhage, otitis media), while 18% of controls had complications, including some deaths

Antigen Prophylaxis
Of those immunized without first being exposed, about 81% of those who did become exposed didn't get the disease, so they said it was 81% effective. That's not exactly how such trials should work; there should be controls.

They claimed this immunity lasted at least 5 months and up to 2.5 years, but I'm not sure how they determined this.

The same was true of those treated after being exposed: 76% didn't get the disease, but again there were no controls reported.

In terms of adverse reactions, some few patients had a short, mild fever, arm redness, or hives, but nothing worse.

Conclusions
So considering the lack of details, controls, and blinding, and how this approach didn't seem to be considered worthwhile either before or after this study, I'm not convinced it's very valuable.

Reference:

Joslin, C. L. & Christensen, T. A. Prophylaxis and treatment of whooping cough with a pertussis antigen: Report of results. Am J Dis Child 60, 1269–1276 (1940).

089 - Treatment of pertussis with the New York State pertussis vaccine

Some investigators in 1936 questioned the effectiveness of any whooping cough vaccine developed thus far, though most thought they were helpful. So Thomas Bumbalo studied a vaccine produced by the New York Department of Health, made of killed bacteria.

The study was in children with siblings, half of whom got the vaccine and the other half didn't. All subjects had been exposed to pertussis though. There were four groups of subjects:

• those who were sick with whooping cough and were treated by vaccination
• those who were sick but were not treated with the vaccine
• those who had been exposed but hadn't yet shown symptoms, and were vaccinated
• those who had been exposed but weren't vaccinated

The first two groups both had 152 subjects, of similar ages and sexes and in the same families if possible. The latter two had 29 and 58 subjects, respectively. Bumbalo explained that mothers in group 3 were hesitant to have their children injected for no apparent reason, and:

"To quote the sentiment of many mothers, whooping cough is 'a mild disease which all kids get sooner or later and they might just as well get it over now.'"

Some things don't change.

So, the results: the average difference between the first two groups in how long they were sick was 32 hours, about 1.3 days. Not too great.

Of the second two, there were 5 cases (17%) in the vaccinated and 6 (10%) in the unvaccinated, though the average severity was milder in the treated. Still, not great.

Still, it wasn't a great study either. Vaccine therapy had already been pretty well demonstrated to be useless, and vaccinating right after the children had been exposed wouldn't help much either; there wouldn't be enough time to form a good immunity. So not much can be concluded.

Reference:
Bumbalo, T. S. Treatment of pertussis with the New York State pertussis vaccine. Am J Dis Child 52, 1390–1396 (1936).

080 - Whooping-Cough or Pertussis

As mentioned before, whooping cough can be pretty hard on children, especially young ones. In this article from 1938, Robert Cruickshank discusses whooping cough and how it compares to some other diseases in the UK at the time.

What Should We Call...

"Whooping cough" is the common term, referring to the shrill intake of air after a bout of intense coughing, but Cruickshank pointed out that even in severe cases of the infection, not all patients actually whoop. And since just "cough" or maybe "whooping and/or non-whooping cough" don't work too well, he suggests "pertussis" as a good alternative. On the other hand, as I discussed in 079, this could cause some confusion too, since not all cases of coughs with whooping are caused by B. pertussis. But obviously both names have stuck with us throughout the years.

Mortality

Different people had different estimates of how many people died from whooping cough. The case-fatality rate seemed to be between 1 and 8.5%, generally higher for younger patients. Though in Glasgow, the reported rate was 27%, and up to 44% for those less than a year old. Pretty bad.

For comparison, the rates for measles, diphtheria, and scarlet fever were 5%, 4%, and 0.4% respectively. So pertussis was the fourth leading cause of death in London ages 0-5 years, killing 434 people per year. The three leading causes were congenital causes, pneumonia, and diarrhea (presumably infections of unknown etiology). Measles was 5th.

Though despite these numbers, the death rates for these diseases had actually been decreasing over the past 70 years, at least for younger children. Cruickshank doesn't discuss why this might be. Could be better treatments, supportive care, immunization (at least for diphtheria), increasing public health in general... not clear.

Prevalence

Keeping track of cases of whooping cough wasn't mandatory throughout the UK at this time, though some areas did so. So it was only possible to estimate the prevalence. Some estimated that 44% of children in London got pertussis before age 5, and 60% by age 10. Measles was similar, diphtheria and scarlet fever less so.

In England, it seemed like pertussis came in two-year intervals, though it seemed different in other countries. This seemed to be because of the addition of susceptible people to the population (newborns), but could also because immunity after infection didn't last too long (possibly only a year; I wasn't clear on this part).

Lab Tests

It was pretty clear at this point that B. pertussis caused whooping cough (most of the time), not some virus. People infected with these bacteria developed antibodies, and antibodies produced from vaccination correlated with immunity to infection. Cruickshank discusses methods for diagnosis, those that work and those that don't.

Treatment and Prevention

Cruickshank says: "Pertussis is a disease of which it may be said that the multiplicity of remedies is an index of therapeutic failure." I think what he means is there a lot of suggestions but not many that actually seem to work. Probably like what I discussed in 078. Supportive care is good, of course, and anything that helps children breathe better. Some thought vaccine therapy or antiserum worked well, especially in the early stages of disease, but it didn't seem clear.

For controlling spread, Cruickshank mainly recommended keeping infected patients away from susceptible children, which makes sense. Pertussis isn't as contagious as measles or chickenpox, for example, so it wouldn't be too hard, even in hospitals. He thought that patients shouldn't be contagious anymore after the 4th week of disease.

If isolation of cases were impossible in any situation, he recommended vaccination as something that seemed effective. He cited Madsen's data (069) and Sauer's, showing effectiveness of their vaccines. But in the interest of more solid data, he recommends a more controlled study, and possibly a program similar to the one in place for diphtheria at the time.

Overall, not much new here, but an interesting perspective.

Reference: Cruickshank, R. Whooping-Cough or Pertussis. The Lancet 232, 33–37 (1938).

078 - Treatment of Whooping Cough with Vitamin C

Another thing I've seen from those who think vaccines are not useful is that vaccines are unnecessary, because large doses of vitamins are cheap and adequate to treat or prevent the relevant diseases. Especially vitamin C, which somehow got a reputation as a disease-busting super-drug. So today I'll be looking at one study that I've seen cited on multiple articles, as well as a couple other related studies.

A. Ascorbic Acid (Vitamin C) Treatment of Whooping Cough¹

Interestingly, Ormerod and Unkauf start off their paper by saying that vaccination so far was the only thing that seemed effective against whooping cough:

"While some protection has been afforded against it by vaccination, treatment of the active disease has not progressed as has treatment of other infectious diseases such as scarlet fever and diphtheria. Madsen reports that, of 1842 vaccinated children, about 25% escaped infection, while of 446 non-vaccinated children less than 2% escaped."

But for those who caught the disease anyway somehow, it'd be very helpful to have a way to treat it, to remove its status as a scary childhood disease:

"In the years 1932-34 there were 45,755 cases of whooping cough reported to the Dominion Bureau of Vital Statistics, with 1982 deaths. Of the fatal cases over 50% occur in the first year of life."

Others had studied the effects of ascorbic acid (vitamin C) on other things, like seeing if it could inactivate diphtheria toxin or inhibiting bacteria directly, but it wasn't clear that its effects weren't only due to its acidity. Even if it can inhibit bacteria in culture, anyway, doesn't mean it can do so in the human body.

Some thought they observed cases of scurvy in pertussis or pneumonia patients, and hypothesized that the body might use vitamin C as a defense mechanism somehow, thus using up its stores. And children seemed to need more than adults. So Ormerod and Unkauf decided to test ascorbic acid's effectiveness in treating whooping cough.

It's actually not so much a study as a series of case reports, since there was no control group. The authors treated pertussis patients with a synthetic form of vitamin C, sold by Roche. All but two of the patients were seven or under; one was 12, and the last was 22. The children all had the characteristic whoop from under a week up to 6 weeks, and starting at various points in the disease, the authors gave them between 125 and 500 mg vitamin C daily. It didn't seem very standardized. Their coughs all disappeared in from 3 days up to 15 days.

Ormerod and Unkauf admit that the data isn't robust enough for good conclusions, but claim that vitamin C seemed to reduce the duration from weeks to days. They don't have any controls though, so it's not really known how the patients would have done without the treatment. Is this study worth anything?

B. Pertussis Endotoxin in the Treatment of Whooping-Cough²

As a comparison, let's look at another study done around the same time, using a treatment that everyone has pretty much discarded as worthless (and had even been discredited at the time, in 1936): vaccine therapy. This is the idea of inducing a better immune response against pathogens currently infecting a person, so the body can better fight it off, rather than producing immunity before an infection is present.

In this study, Thompson wanted to try to induce an immune response against bacterial toxins produced in whooping cough patients by injecting purified toxin. Others had tried this, but the studies weren't done well, so it was hard to tell if there was really an effect.

Thompson used a procedure similar to Krueger's (076) for producing the toxin. He found that it had little effect when injected into rodents, but it often produced an allergy-like reddening in children. Possibly an immune reaction. In whooping cough patients, it seemed to exacerbate the symptoms sometimes, which doesn't seem surprising. So he tried to use lower doses to avoid this reaction.

He studied a group of 403 children admitted to the hospital with whooping cough. He gave 132 of them daily injections with the toxin, and the others were controls. Some of the controls even got placebo in the form of saline injections. The children received some other treatments too, seemingly to treat symptoms.

But even so, it was tough to compare the two groups, because there weren't specific endpoints. It didn't seem like severity was different, but maybe the duration was shorter, like the treatment accelerated the disease process, making it end sooner.

Possibly there was an effect in those treated early in their infection, shortening the case and reducing severity. But Thompson tried to replicate the result in another 71 patients, treating them early, and again it seemed to reduce the duration but not severity. So of questionable use overall.

C. Vitamin C in Treatment of Whooping-cough³

Responding to both of the above studies, apparently Douglas Gairdner was dubious:

"It also seems true to say that although 'nearly every newly discovered remedy in ancient and modern times has at one time been advocated for treatment of this disease', there is not one that has been proved to have an appreciable effect on its course. Of vaccine or endotoxin therapy, lately so enthusiastically recommended, the conclusion...'that the more carefully the results are controlled the less impressive do they become' seems inescapable in light of recent reports."

Ormerod's results from North America using vitamin C showed a much shorter whooping cough duration than what was common in the UK, so Gairdner wanted to try to replicate those results. He used naturally derived ascorbic acid, donated by Roche, to avoid a possible difference in effect from the synthetic (like Ormerod used); a few younger children got the synthetic kind because it was less bulky. He tried to use doses similar to Ormerod, several hundred mg, much more than the daily requirement for normal children (about 25 mg). Control subjects were given a placebo, cod liver oil and a couple other things that were known not to affect the disease.

In total, Gairdner treated 21 children, and kept another 20 as controls. 20% of each dropped out. Cases were confirmed by culturing the bacteria and hearing the cough. All cases had been coughing for less than 3 weeks when they started treatment. He followed them by getting the mothers to record the number of coughs each day and night until they stopped coughing at night. He also weighed the children to see if the disease was impairing their growth.

In Ormerod and Unkauf's study, they started treating an average of 9 days after disease started, and it lasted an average of 14 days longer, for 23 days total. 

Gairdner started treating his patients 10 days after the disease started on average (14 days for controls), and the disease lasted an average of 25 days after treatment (27 days for controls), for a total of 35 days (or 41 for controls). Apparently there was no statistically significant difference between the groups, nor for the difference in weight gained during the disease period (0.01 lb difference). Severity wasn't really measured.

So both treated and controls had much longer disease than in Ormerod's study, at least 12 days. Gairdner's conclusions:

"The assertion of Ormerod and UnKauf that the paroxysmal period of the disease is shortened 'from a matter of weeks to a matter of days' was not confirmed."

"As there were no controls in the Canadian series, however, it is impossible to judge whether the natural course of the untreated disease varies in the two countries, or whether the considerable difference in the course of the disease in the present and in the Canadian series is due, for instance, to the application of a more rigorous standard of cure in the former series."

"It is considered that the statement that the administration of vitamin C in whooping-cough has an effect upon the course of the disease is at present unproven."

It's possible that synthetic vitamin C worked better than naturally-derived kind, though these studies can't really be used to conclude that either. But it would be interesting.

Later studies commented on the vitamin C studies discussed:

"Gairdner has reported a failure to affect the course of whooping cough using the method of Omerod (sic), but Gairdner also failed to test for a deficiency before instituting treatment."⁴

"Gairdner in a controlled experiment found that the duration of illness in a group receiving vitamin C was shorter than in controls. The difference in the two groups was not a significant one, and he considered that the alleged benefits of vitamin C in whooping cough were unproven."⁵

The first statement, by J.B. Youmans, is slightly puzzling to me, because the original paper doesn't indicate that Ormerod and Unkauf tested for deficiency either. All just assumed that the doses they were giving were high enough to correct any deficiency. If it is a legitimate criticism, it seems to show that vitamin C would only be beneficial if there is a real deficiency.

References:

1.

Ormerod, M. J. & Unkauf, B. M. Ascorbic Acid (Vitamin C) Treatment of Whooping Cough. Can Med Assoc J 37, 134–136 (1937).

2.

Thompson, A. R. Pertussis Endotoxin in the Treatment of Whooping-Cough. The Lancet 230, 733–736 (1937).

3.

Gairdner, D. Vitamin C in Treatment of Whooping-cough. British Medical Journal 2, 742–744 (1938).

4.

Youmans, J. B. The Influence of Vitamin Deficiencies on Other Diseases. Ann Intern Med 13, 980–986 (1939).

5.

Glazebrook, A. J. & Thomson, S. The Administration of Vitamin C in a Large Institution and Its Effect on General Health and Resistance to Infection. The Journal of Hygiene 42, 1–19 (1942).

070 - Immunization with Bacillus pertussis vaccine

As today's article states near its beginning:

"Most whooping cough patients need no physician, but those who do, need him badly." -Pospischill

Louis Sauer was one of the first to develop a whooping cough vaccine that actually seemed to work, at least sometimes. This was another article giving some data of efficacy.¹

As usual, the bacteria to make it were from fresh isolates of the disease, grown on human blood and suspended/killed in saline plus a little phenol.

Sauer first determined that the vaccine didn't work for vaccine therapy (i.e. using a vaccine to treat a disease, rather than prevent it). Not surprising; that concept didn't work too well in general.

So the next test would be for prophylaxis, preventing the disease by giving the vaccine to people before they were exposed to the disease. So he injected it into 394 children, most of whom had an older sibling known to be likely susceptible to pertussis (i.e. they hadn't been vaccinated or caught the disease before); these siblings were the controls. He used 3 injections total; he tried a single larger dose for some, but it seemed more prone to side effects.

Sauer reported that he did warn parents of the children about potential side effects, such as temporary fever and reactions at the site of injection, but all of them were eager for the treatment except for two, who refused it.

So within these children, over the course of 5 years, there were about 191 exposures to whooping cough, but not a single vaccinated subject got the disease. Of the controls, 31 got it, including many who were siblings of the vaccinated. There was definitely a lot of exposure of the vaccinated from their siblings, including as intimate as kissing (platonic, of course).

So Sauer concluded that his vaccine produced immunity after four months, at most, which lasted at least a few years. He recommended vaccination at ages 6-12 months, because immunity could definitely be produced at that age, and pertussis is most dangerous within the first two years.

This study had problems, of course, and isn't up to modern standards at all, but the results are fairly striking.

There was some discussion between physicians published after the main article, some of which was related and interesting:

"Dr. Sauer seems to have found a method of preparation and a method of administration of pertussis vaccine that will protect a child from whooping cough just as certainly as toxoid protects against diphtheria. His success in immunizing against pertussis is probably due to two factors. The first factor is the preparation of the vaccine. He uses only fresh cultures obtained every few months from active proved cases of pertussis. The second contributing factor is the tremendous dosage." -Dr. Raymond Schowalter

"Three or four months should elapse or intervene between completion of the vaccine administration and exposure to the disease. During the five years that this work has been going on, people wanted their children injected while whooping cough was in their neighborhoods. This was done and in a number of cases, within one or two months after the injections were begun, these children contracted pertussis. But in no case in which the time interval was more than three months has any child contracted pertussis, although, as the charts show, eighteen were intimately exposed to control cases in the family." -Louis Sauer 

 Also a later publication made an interesting remark on the quality of this study:

"Sauer's reports since 1933 as to the prophylactic value of [his vaccine] seem convincing, except for the fact that he does not fully discuss his results in an adequate number of control children."²

References:
1. Sauer, L. Immunization with Bacillus pertussis vaccine. JAMA 101, 1449–1453 (1933).
2. Siegel, M. & Goldberger, E. W. Active immunization of tuberculous children against whooping cough with Sauer’s vaccine. JAMA 109, 1088–1092 (1937).

014 - Three Cases of Probable Cancer Transplantation from the Use of the Gilman Vaccine

I skipped 1908 through 1910 because it was pretty much entirely just a big debate about the effectiveness of vaccine therapy, which I've already talked about enough, and since it isn't really used much today (if at all), it isn't in line with my goal of evaluating the safety and effectiveness of modern vaccines.

However, some such studies can be interesting and unique enough to be worth reading and writing about. This is one of them: a bit horrifying, actually.

While most people were trying to use vaccines and vaccine therapy for all kinds of different bacterial infections, some physicians in the Philippines, Gilman and Coca, had the idea of treating cancer with the same method: after removing a tumor, inactivating it somehow and injecting it back into the patient to stimulate an immune response against the material.

Unfortunately, the inactivation procedure apparently didn't always work, so the current series of case reports details several cancer patients who apparently experienced a sort of artificial metastasis when the tumor material injected into them started growing new tumors at the injection site.

The treatment itself sounded rather unpleasant: injection into the abdomen, sometimes with seizures as a side effect. But apparently the method used to inactivate the cancerous material before injection (5% phenol) was inadequate. Fortunately, it seemed like doctors received this article as a warning and were more careful in the future.

On the face of it, the treatment doesn't seem implausible. Cancer cells are different in some ways from healthy tissue, theoretically susceptible to immune attack, so inducing a stronger response against them might be helpful. People even now are trying to induce immune responses against certain cancers (see here). But it is very tricky, considering how similar cancer cells can be to healthy cells (they share the same ancestor cells, after all). It might be possible to cause some autoimmune disorders using this cancer vaccine therapy method, I would think, so it's probably best that it is no longer in use.

Citation: Coffey, W. B. Three Cases of Probable Cancer Transplantation from the Use of the Gilman Vaccine. Cal State J Med 9, 129–130 (1911).

013 - The Opsonic Index as a Guide to regulate the use of Vaccines in the Treatment of Disease

This paper seems to be near to the inception of immunology, obviously an important area of research into the mechanism and function of vaccines. The authors report on work done by a number of researchers (mostly women, interestingly) evaluating the opsonic index, mentioned here before.

To recap: the opsonic or phagocytic index is a measure of the activity of white blood cells in consuming bacteria they encounter.

Research previous to this paper had discovered that the increased activity of the white blood cells (aka leukocytes) of vaccinated animals was not something inherent to the cells themselves—isolated leukocytes from unvaccinated animals had the same activity. Rather, the increased activity came from some other component of the serum of the animal (the liquid, cell-free portion of the blood). A.E. Wright referred to this serum element as "opsonins," which bind to the pathogen and induce phagocytosis, that is, uptake by white blood cells.

According to Wright, who developed the opsonic index method, determining this index value is important for administering vaccine therapy, because too high a dose can actually reduce a person's immunity to a pathogen.

The way this opsonic index is determined is to take equal amounts of bacteria, blood cells, and serum and mix them together, incubate for 15 minutes, then examine them under a microscope and count how many bacteria each leukocyte has taken up into itself.

The authors here describe a number of factors that must be controlled to get an accurate opsonic index value; failure to control them can introduce significant artifical variation. Such factors include number of leukocytes counted from each sample (at least 50 is important, up to 150; speaking from experience, that sounds like a seriously unpleasant experience for the person doing the counting, staring into a microscope for so long; especially since it is also important for just one person to do all the counting, since different people count the numbers differently and induce more variation), and slight variations in mixture proportions can introduce variation too. Because of these difficulties, it often took so long to finish a counting that the vaccinator had to go ahead and treat the patient before actually getting the results.

There was some investigation into the nature of these opsonins, too. Those from unvaccinated serum were more vulnerable to disruption by heating than those from vaccinated, and the former seemed to bind more generally—they could be titrated or removed from the serum using common "complement absorber" compounds—whereas the elements from vaccinated serum were more heat-stable and only bound well to the pathogens that had been vaccinated against. The latter, they referred to as "antibodies." We know more about these elements in modern times, of course, as members of the innate vs. adaptive immune systems.

The authors also report a number of trials of vaccine therapy against a variety of pathogens, using opsonic index measurements to inform the therapy. In most of the cases it didn't seem to help very much, and the index readings were inconsistent, so it didn't seem as useful as Wright made it out to be.

Citation: Park, W. H. & Biggs, H. M. The Opsonic Index as a Guide to regulate the use of Vaccines in the Treatment of Disease. J Med Res 17, 77–88 (1907).

010 and 011 - On the Treatment of Acne, Furunculosis, and Sycosis by Therapeutic Inoculations of Staphylococcus Vaccine

Next up is a pair of articles by the same researcher that helped develop the antityphoid vaccine (009), Almroth Edward Wright. Apparently he is quite a character, worth reading about; he predicted the rise of antibiotic-resistant bacteria and was a big advocate of preventative medicine.

In this pair of articles, Wright was attempting to develop a therapeutic (rather than preventative) vaccine against Staphylococcus, a common cause of skin infections such as boils (aka furunculosis) and hair follicle infection (sycosis). The preparation of the vaccine was similar to that of the antityphoid: grow up the bacteria, kill them somehow, and inject this into the patient. Often he used bacteria cultured from the patient’s own infection.

The first paper is a series of case reports, with some in-depth data and graphs(1). The second is another series of descriptive case reports of patients treated with this therapy(2). In each case, it appeared to help the patient’s current problem, but each patient seemed to suffer recurrences, the same or different, pretty often.

One interesting aspect to these reports is the measurement of phagocytic/opsonic index, a measure of how well the treatment increased the immune response. It did seem to increase after the vaccination. Other articles citing these papers give some more details:

Wright and Alexander Fleming developed technique called opsonic/phagocytic index to measure levels of antibodies against pathogen.

"This was considered necessary because by giving too large a dose of vaccine one could lower the antibody level in what was called a 'negative phase' to such an extent that the patient might become worse because he did not have a sufficient margin of resistance to safeguard him against any generalization of the infection....Fleming and his colleagues carried out no less than 16,000 opsonic tests in one year, each of which required half an hour."(3)

"Here again, a lack of adequate controls confounds the analysis. Wright's methods for measuring opsonizing activity were criticized by the renowned biostatistician Karl Pearson who deplored his cavalier indifference to statistical tests of significance: Pearson concludes one paper critical of Wright's data analysis with the exhortation 'Statistics on the table, please!'"(4)

"No adequately controlled clinical trials were undertaken to demonstrate the effectiveness of these forms of therapy."(5)

Sums it up pretty well, I think: not great quality. I hope to learn more about vaccine therapy in future reading though.

References:
1. Wright, A.E. Notes on the treatment of furunculosis, sycosis, and acne by the inoculation of a staphylococcus vaccine,: and generally on the treatment of localised bacterial invasions by therapeutic inoculations of the corresponding bacterial vaccines. The Lancet 159, 874–884 (1902).

2. Wright, A. E. On the Treatment of Acne, Furunculosis, and Sycosis by Therapeutic Inoculations of Staphylococcus Vaccine. Br. Med. J. 1, 1075–1077 (1904).

3. Hare, R. The scientific activities of Alexander Fleming, other than the discovery of penicillin. Med. Hist. 27, 347–372 (1983).

4. Burke, D. S. Vaccine therapy for HIV: A historical review of the treatment of infectious diseases by active specific immunization with microbe-derived antigens. Vaccine 11, 883–891 (1993).

5. Stein, D. S., Timpone, J. G., Gradon, J. D., Kagan, J. M. & Schnittman, S. M. Immune-Based Therapeutics: Scientific Rationale and the Promising Approaches to the Treatment of the Human Immunodeficiency Virus-Infected Individual. Clin. Infect. Dis. 17, 749–771 (1993).