Protection against infection
The COVID vaccines were promoted as the tool that would end the pandemic and return life to normal. However, the clinical trials for the Moderna, Pfizer, AstraZeneca, and Johnson & Johnson vaccines did not test or even measure the extent to which their products reduce infection. Meaning, at the time of receiving the Emergency Use Authorization, there was no study to support the claim that the vaccines prevent infection. This was publicly acknowledged by Moderna, Pfizer and the World Health Organization (WHO). The 90% + effectiveness touted by the vaccine manufacturers was for reducing the severity of symptoms, not reducing infections.
Despite this public health officials and government leaders repeatedly claimed the vaccine stops infection:
In August 2021 a study from the Mayo Clinic showed that after six months, the Pfizer vaccine provided just 42% effectiveness at reducing infection, and an Israeli study showed about a 16% effectiveness for symptomatic infections. A study in The Lancet showed a dramatic decline in vaccine-induced immunity over just five months. Another study in the New England Journal of Medicine (NEJM) found that the decline accelerates after the fourth month to reach only about 20% effectiveness by the fifth month.
Several months after the start of the vaccination campaign the fact that the vaccines do not reduce infections became clear in real-world data as well. After comparing 68 countries and almost 3,000 counties in the U.S., an article in The European Journal of Epidemiology concluded that there was no difference between jurisdictions that were highly vaccinated and those that were less vaccinated when it came to new COVID infection. In fact, the opposite was found in many instances, that higher rates of vaccination correlated with increased infections. This phenomenon was also observed in a comparison between European countries.
According to Israeli Health Ministry data, during the fourth wave in summer 2021, infections in Israel were found to be at the same rate in the vaccinated and unvaccinated.
Lest one think that vaccination could reduce an infected person’s ability to infect others, reports from health officials in the U.K.,  the CDC, and other research  show this is not the case. Once infected, the vaccinated have similar viral loads as the unvaccinated.
This new evidence prompted Bill Gates to concede that “we need a new way of doing the vaccines.”
With the emergence of Omicron in December 2021, vaccination was shown to be correlated with higher infection rates, and likely a contributor to COVID infection and transmission.
A number of key studies reported vaccinated individuals had negative effectiveness against infections.
One study published in December 2021 looked at the effectiveness of both Pfizer and the Moderna vaccine and found that during the 91-150 days since vaccination, the vaccine effectiveness fell solidly into negative territory -76.5% for Pfizer, and -39.3% for Moderna. 
Real-world data from the UK, Scotland, Denmark Canada, Germany, South Africa, New Zealand, and Israel supported this conclusion showing that vaccinated individuals were testing positive significantly more than the unvaccinated.
Scientists are still investigating how the vaccine might affect the immune system. One study explores three possible ways in which the vaccine suppresses immune response. The paper concludes, "should any of these potentials be fully realized, the impact on billions of people around the world could be enormous and could contribute to both the short-term and long-term disease burden our health care system faces." 
Another study found that 93% of the unvaccinated control group produced the SARS-CoV-2 anti-nucleocapsid antibody after infection, while only 40% of the vaccinated produced this antibody at detectable levels after infection, suggesting that the vaccinated may be more susceptible to future infections.
For more, see the Negative Effectiveness section of the Pedia
Protection against serious illness:
The other aspect of COVID vaccines’ effectiveness is their ability to prevent serious illness and death. Before examining this aspect, the issue should be looked at in the context of other treatments and prophylactics, see early treatments. In addition, the absolute risk associated with becoming seriously ill from COVID needs to be better appreciated.
Comparing the chances of serious illness in those who have been vaccinated to those who have not is called Relative Risk Reduction (RRR). An article published in the prestigious Lancet explains that “RRR should be seen against the background risk of being infected and becoming ill with COVID-19.” In other words, RRR does not consider the chance of becoming infected. The chance of becoming infected is known as the “... absolute risk reduction (ARR), which is the difference between attack rates with and without a vaccine. . .” ARR provides a more real-world measure of effectiveness. Just as an umbrella is very effective at keeping out the rain it is not any more effective if it’s not raining. So too, a COVID vaccine is not any more effective in absolute terms regardless of its Relative Risk Reduction.
The ARR for COVID vaccines ranges from 0.84% to 1.3% depending on the vaccine. The Lancet article authors explain that “ARRs tend to be ignored because they give a much less impressive effect size than RRRs.”
While most other data show that vaccination protects against COVID hospitalizations and death, that protection comes with risks of other injury and death. To see how the risks of death from the vaccine match up with the risks of death from COVID, it helps to look at the vaccine's impact on all-cause mortality.
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 “These trials all clearly focus on eliminating symptoms of Covid-19, and not infections themselves”
 “We will not have sufficient concrete data to prove that this vaccine reduces transmission.”
 “WHO Chief Scientist: No evidence vaccines will prevent COVID infection“
 “16% effective against symptomatic infection for those individuals who had two doses of the shot back in January”
 “Effectiveness against infections declined from 88% (95% CI 86–89) during the first month after full vaccination to 47% (43–51) after 5 months”
 “Once they are infected there is limited difference in viral load (and Ct values) between those who are vaccinated and unvaccinated. Given they have similar Ct values, this suggests limited difference in infectiousness”
 “Vaccinated and unvaccinated individuals have similar viral loads”
 “New research suggests vaccinated people can spread the virus”
 “Vaccinated persons who become infected with SARS-CoV-2 to be no less infectious than unvaccinated persons”
 “No significant difference in viral load between vaccinated and unvaccinated people”
 91-150 days since vaccine protection: vaccine effectiveness -76.5% for Pfizer, -39.3% for Moderna
“Omicron infection ≥240 days after a second dose was -174%”
Email questions or comments to [email protected]