You may wonder why I keep harping about inadequate testing and safety concerns. In addition to my experience treating patients who became ill following vaccinations, I have also reviewed the vaccine safety literature. There are many stories of vaccines that appeared safe, but were later found to be dangerous. The Edmonston-Zaghreb "high titre" measles vaccine, designed to give immunity to infants at the age they are most susceptible to a bad outcome from measles infection, is one such story.
Children died at higher rates overall, in a number of countries, after receiving this measles vaccine compared to an earlier measles vaccine. Yet twenty years ago, this was the measles vaccine
recommended by the WHO for children most at risk from measles. WHO later pulled its recommendation, but infants received this vaccine for several years before the problem was discovered.
No, this is not the live measles vaccine of the 1960s I discussed earlier. That one caused a worse disease than measles once you were exposed to measles. This one increased the death rate from diseases other than measles. No one ever explained why. So the same 'mistake' could happen with other vaccines, since we don't know what the mistake was.
This is why I point out that vaccine science is in its infancy. Vaccines are all derived empirically: scientists don't really know which ingredients will give the desired result, so they just test various prototypes till one looks 'good.' Conversely, they cannot tell which vaccines will turn out to be 'bad' until the vaccines have undergone a lot of testing.
It is relatively easy to see how effective a vaccine will be in terms of antibody levels (though the antibodies we measure do not always predict true immunity to infection). You just measure them. It is much harder to test safety. You don't know ahead of time what side effects will be caused by the vaccine, so you have to consider every adverse event that occurs after a vaccination as a possible side effect. However, statistics tells us that some adverse events will appear to occur at higher than expected rates following vaccination, but that is to be expected. So regulators tend to ignore many adverse events that occur at high rates, assuming they are statistical "blips." You would need to observe large numbers of people for long periods of time, and this is not done in prelicensure vaccine studies.
A few adverse reactions are taken very seriously: those that are well known to be caused by vaccines. These include, for example, Guillain Barre Syndrome and brachial neuritis (nerve impairment near the site of the injection). Because they are rare and severe conditions, when they occur after a vaccine people notice.
Might asthma or diabetes be caused or worsened by vaccines? They are common illnesses. Even though hospitalizations for them occurred statistically more often in soldiers after anthrax vaccination, no targeted study has been undertaken to see if they are, in fact, side effects of vaccination. (FDA gave me this answer to a FOIA request.)
The bottom line is that for most illnesses, the type of research that would resolve whether a vaccination contributed to or caused a specific illness has never been done.
Here is a WHO abstract on the Edmonston-Zaghreb high titre measles vaccine, fyi:
Wkly Epidemiol Rec. 1992 Nov 27;67(48):357-61.
Expanded Program on Immunization (EPI). Safety of high titre measles vaccine.
Unexpected results suggesting decreased survival when compared with standard titre vaccine administered at 9 months of age have been found in some field studies evaluating the performance of high titre measles vaccine. Analytical difficulties have arisen because the studies were not specifically designed to measure survival. Nonetheless, careful analysis of the results from all of the high titre vaccine trials showed decreased survival of high titre vaccine recipients, in areas with high background mortality rates, compared with recipients of standard measles vaccines at 9 months. No systematic biases could be found in the studies to explain these differences. Statistical analysis of these data suggested that the findings were unlikely to be attributable to chance alone. The panel recommended that high titre measles vaccine derived from the original Edmonston measles vaccine isolate should no longer be recommended for use in immunization programmes. Further post-licensure field studies of new measles vaccines should take into account the results of these studies. Additional detailed epidemiological studies in populations that have received high titre vaccines and their controls were encouraged.
PIP: A WHO group recommended in October 1989 that health workers in countries where measles is a significant cause of death for infants under 9 months old use the high titer Edmonston-Zagreb (EZ) measles vaccine for 6-month old infants, or as soon as possible thereafter, instead of the standard titer vaccine at 9 months. In 1990, reports from Senegal and Guinea Bissau showed that infants receiving the high titer measles vaccine before 9 months old were dying at a faster rate than those who received the standard titer vaccine at 9 months of age. These reports precipitated a WHO consultative meeting in February 1991 where participants reviewed the data in question. They considered the data to be inconclusive and recommended that countries continue to use the 1989 guidelines. Other issues later emerged causing WHO to reconvene the working group to reexamine all the safety immunogenicity, and efficacy data of the high titer measles vaccines in infants under 9 months old. Participants at the October 1991 meeting found that a link between the high titer measles vaccine and decreased survival was consistent in the 4 studies with high background infant mortality (relative risk = 1.25; p = .05), but such an association did not exist in the countries with low background infant mortality, suggesting that the vaccine had a multiplicative effect. In 3 of the 4 studies, girls were more likely to experience greater reduced survival than boys (p .02). In all 4 studies, the dose of the vaccine was a leading factor linked to reduced survival. The EZ vaccine was more immunogenic than the Schwartz vaccine at 4-6 months, particularly when maternal antibodies were present. The participants examined a mathematical model based on the submitted data and it indicated that the high titer vaccine would provide only a marginal benefit. They concluded that immunization programs should no longer use the EZ vaccine and that no more field trials of this vaccine should occur.
Children died at higher rates overall, in a number of countries, after receiving this measles vaccine compared to an earlier measles vaccine. Yet twenty years ago, this was the measles vaccine recommended by the WHO for children most at risk from measles. WHO later pulled its recommendation, but infants received this vaccine for several years before the problem was discovered.
No, this is not the live measles vaccine of the 1960s I discussed earlier. That one caused a worse disease than measles once you were exposed to measles. This one increased the death rate from diseases other than measles. No one ever explained why. So the same 'mistake' could happen with other vaccines, since we don't know what the mistake was.
This is why I point out that vaccine science is in its infancy. Vaccines are all derived empirically: scientists don't really know which ingredients will give the desired result, so they just test various prototypes till one looks 'good.' Conversely, they cannot tell which vaccines will turn out to be 'bad' until the vaccines have undergone a lot of testing.
It is relatively easy to see how effective a vaccine will be in terms of antibody levels (though the antibodies we measure do not always predict true immunity to infection). You just measure them. It is much harder to test safety. You don't know ahead of time what side effects will be caused by the vaccine, so you have to consider every adverse event that occurs after a vaccination as a possible side effect. However, statistics tells us that some adverse events will appear to occur at higher than expected rates following vaccination, but that is to be expected. So regulators tend to ignore many adverse events that occur at high rates, assuming they are statistical "blips." You would need to observe large numbers of people for long periods of time, and this is not done in prelicensure vaccine studies.
A few adverse reactions are taken very seriously: those that are well known to be caused by vaccines. These include, for example, Guillain Barre Syndrome and brachial neuritis (nerve impairment near the site of the injection). Because they are rare and severe conditions, when they occur after a vaccine people notice.
Might asthma or diabetes be caused or worsened by vaccines? They are common illnesses. Even though hospitalizations for them occurred statistically more often in soldiers after anthrax vaccination, no targeted study has been undertaken to see if they are, in fact, side effects of vaccination. (FDA gave me this answer to a FOIA request.)
The bottom line is that for most illnesses, the type of research that would resolve whether a vaccination contributed to or caused a specific illness has never been done.
Here is a WHO abstract on the Edmonston-Zaghreb high titre measles vaccine, fyi: