Dr. Anthony Fauci has finally acknowledged that there had always been good scientific reasons to believe that vaccines against the respiratory virus that causes Covid-19 — SARS-CoV-2 — would provide limited protection against infection that would not be long-lasting. That is precisely what happened: It quickly became apparent that protection against transmission lasted just a few months, and initial effectiveness declined as each new viral variant proved more contagious than its predecessor. Yet Fauci insisted that repeated vaccines were needed for everyone and until recently pushed for vaccine mandates. This has resulted in shortages of essential workers, poorer educational outcomes, and diminished trust in public-health authorities.
Last month in an article in the journal Cell Host & Microbe, Fauci wrote that vaccines against respiratory viruses generally provide “decidedly suboptimal” protection against infection and rarely produce durable, protective immunity. The reason is that most of these viruses, such as influenza, which causes the flu, and SARS-CoV-2, have short incubation periods during which they infect the respiratory mucosa and rapidly replicate there without spreading systemically. Moreover, according to Fauci, the human immune system has evolved to tolerate respiratory viruses during short intervals of mucosal viral replication. This leads to illness and onward transmission without eliciting a systemic immune response.
These factors negate the effectiveness of vaccines, which typically rely on systemic responses to viral exposures. Respiratory viruses that replicate rapidly in the mucosa cause short-duration illnesses and transmission to others all before the immunologic defenses put in place by vaccines can be brought to bear. Vaccines against the influenza virus that causes the flu, for example, have averaged only 40 percent effectiveness against infection over the last 17 influenza seasons, ranging from 10 to 60 percent. And, as Fauci acknowledged, “the duration of vaccine-elicited immunity is measured only in months.”
There are a few successful vaccines against respiratory viruses with long incubation periods such as the ones that cause measles, mumps, and rubella. Unlike the short-incubation viruses, these viruses rapidly move from the mucosa to spread systemically so that they elicit strong immunologic responses and long-term immunity.
In addition, many respiratory viruses, including both SARS-CoV-2 and influenza, are more likely to mutate than the measles, mumps and rubella viruses, leading to more-rapid emergence of new variants. This makes production of vaccines with long-lasting protection difficult.
Fauci concluded that vaccines for most respiratory viruses such as influenza and SARS-CoV-2 “have common characteristics: they elicit incomplete and short-lived protection against evolving virus variants that escape population immunity.” Their primary utility is to reduce the risk of severe disease, hospitalization, and death. As Dr. Paul Offit wrote in the New England Journal of Medicine, “for vaccines against SARS-CoV-2, a mucosal infection with a short incubation period, protection from severe disease is the only reasonable and attainable goal.”
Given this background, the poor effectiveness of the Covid-19 vaccines should have been reasonably foreseeable. In addition, Fauci noted that all of the vaccines that are successful against systemic respiratory viruses — generating broader and longer-lasting immunity — are systemically replicating live-virus vaccines that fully encounter the host mucosal and systemic immune system. None of the Covid-19 vaccines fall into this category.
Early reports claimed 90 percent effectiveness in preventing symptomatic and asymptomatic infection with SARS-CoV-2. Predictably, this effectiveness lasted for only a few months. And when variant SARS-CoV-2 strains emerged, “deficiencies in these vaccines reminiscent of influenza vaccines” became apparent, according to Fauci. During the Delta-variant surge in the summer of 2021, short-term vaccine effectiveness declined to 66 percent. The figures have steadily declined since with each successive variant.
When vaccines first became available in December 2020–January 2021, Covid cases were surging, and there were still large numbers of people who had not been infected and gained natural immunity after recovery. Vaccination requirements for health-care workers in hospitals and nursing homes could be justified to protect those essential workers and to protect the vulnerable people they cared for. But within a short time, it became clear that, while Covid vaccines continue to protect against severe illness and death, they had largely lost their ability to stop viral transmission.
Nevertheless, Fauci advocated vaccine mandates for schoolchildren under twelve in August 2021, more than a year after it was clear that this age group had virtually no risk of severe Covid disease or mortality. Months later he defended generalized mandates because “society needs to be protected. And you do that by not only protecting yourself, but by protecting the people around you by getting vaccinated.”
Fauci had to have known this statement was inaccurate based on the scientific factors he recounts in his recent article and on the evolving data showing declining vaccine effectiveness that he had access to. Whatever his motivations for making this erroneous assertion, the policies it inspired were disastrous.
Workers who were, perhaps ill-advisedly, willing to defy vaccine mandates and assume the risk of their own severe illness were fired, even though vaccines would protect neither them nor their co-workers from infection. Thousands of essential workers including firefighters, police officers, and military and medical personnel lost jobs and have yet to be replaced. Staffing shortages are common.
Schoolchildren whose parents understandably doubted the need to vaccinate them were excluded from school, compounding the loss in in-person classes from earlier school closures. The educational losses have been staggering and disproportionately affect already disadvantaged communities.
Booster shots, particularly the recently introduced bivalent boosters, have been promoted by Fauci and others with little or no experimental evidence that they reduce transmission for more than brief periods of time. Offit concluded that “booster dosing is probably best reserved for the people most likely to need protection against severe disease — specifically, older adults, people with multiple coexisting conditions that put them at high risk for serious illness, and those who are immunocompromised. . . . We should stop trying to prevent all symptomatic infections in healthy, young people by boosting them with vaccines containing mRNA from strains that might disappear a few months later.”
Perhaps the most serious side effect of Fauci’s prolonged reluctance to acknowledge the predictable and eventually widely known shortcomings of Covid vaccines has been to undermine trust in public-health authorities. Throughout the pandemic, health pronouncements from federal authorities have often been confusing and sometimes outright misleading. The most important factor in combating future pandemics will be people’s voluntary risk-avoidance behaviors, including their willingness to comply with reasonable public-health advice. If people have little faith in the advice they receive, the consequences could be calamitous.