The Biden administration has approved a fourth vaccine against Covid-19 for all Americans over the age of 50 and for all adults who are immunocompromised. But does this mean that everyone who qualifies has to rush to the pharmacy or GP to get it?
The short answer is that it depends on both your personal risk and what happens to the pandemic. To make matters more confusing, public health guidelines have become more nuanced as more booster shots are allowed. While public health experts unanimously urged people to get their first and second injections last year, they were more divided over the third injection when it was approved late last year, at least until the emerging microwave wave made the first round of boosters more urgent. made.
With the fourth shots getting the hang of federal officials, public health experts emphasize that individual circumstances should determine whether you should get another booster shot right away. Some experts are: skeptical that more shots are really needed for people except maybe the older age groups (for example, people over 65) and for people with certain immune system disorders. Others simply say that the evidence is mixed and that people should make their own judgment, in consultation with a doctor.
“I don’t think it’s a right or wrong answer with some obviously overwhelming evidence,” Alessandro Sette, an immunologist at the La Jolla Institute for Immunology, told me. “That might make it a little confusing for everyone.”
For those with conditions that compromise their immune response, Sette was unequivocal: Yes, get your shot as soon as you qualify. (The CDC said people have to wait four months between doses.) Those people usually benefit less from the vaccines so far and, as the Washington Post reportedis one of the reasons the Biden administration is pushing ahead with a fourth shot, to provide people with protection in the event of a new Covid-19 wave created by the omicron BA.2 variant.
For otherwise healthy people over 50, it becomes more of a personal choice. Sette herself is over 50 and is therefore eligible. “I’m glad I have the option,” he said. “I’m in no rush to get it.”
Other countries have limited their fourth shot to people much older than 50 – over 70 in Germany and more than 75 in the United Kingdom, for example, along with immunocompromised people in both countries. The risk of serious Covid-19 complications increases with age, so experts say getting a new booster is most urgent for the oldest age cohorts, especially in the event that the new omicron BA.2 variant hits a new wave. of infections in the US.
“This gives some people who got boosters early on, more protection against BA.2 than they have now,” Bill Hanage, a Harvard University epidemiologist, told me via email. “Is it necessary? Not for younger people. Older people? Very likely.”
For people closer to 50, it may be more a matter of personal taste and risk tolerance. Monica Gandhi, an infectious disease physician at UC San Francisco, pointed out: a survey among health professionals who found no evidence that a fourth injection offered more protection or reduced viral loads for people under the age of 65. With that in mind, she said she would advise a fourth injection only for patients over 65.
Preliminary investigation from Israel found that a fourth shot reduced the risk of death for people over 60. But it must be remembered, Sette said, that any improvement from a fourth shot starts at a very high baseline. The three-shot protocol recommended by the health authorities had already proven to be very effective in preventing the most serious consequences for most people.
And preventing more hospitalizations and deaths, many experts say, should be the primary goal of the vaccines, as opposed to preventing infections.
The dual immune response of the human body makes the former much easier than the latter. When a person is vaccinated, they have a surge of antibodies, which can prevent a Covid-19 infection from occurring at all. But over time, those antibodies, that first layer of defense, will start to wane. Even with booster shots, the evidence indicates the boost is in antibodies only temporary†
But that doesn’t mean a person is completely vulnerable to the coronavirus if they catch it again. Their bodies still have memory cells that can recognize Covid-19 and start producing antibodies if the person becomes infected. That process may not happen fast enough to prevent an infection. But it should prevent most people’s symptoms from getting so severe that they end up in the hospital.
For the elderly and immunocompromised, there is a stronger case for trying to keep antibody levels high, as they tend not to be as strong from an immune response from vaccination in the first place. We don’t necessarily want to risk infection in those people because there are cases of vaccinated elderly or people with immune disorders contracting Covid-19 and getting very sick or even dying.
Hanage argued that to prevent more serious illness and death, it is paramount to give people who have not yet had a third dose their first booster shot. The United States has lagged behind its peers like the UK by giving even the vulnerable population, such as the over-65s, a third chance.
“While the fourth shots have value in these populations, getting the third shots would be even better in vulnerable people who haven’t received them yet,” he said.
And for younger and healthier people, they can be more confident that the protection they’ve received from three shots is resilient.
Sette said he would probably get a fourth chance eventually, but he can wait to get it until closer to a family vacation he has planned for the summer. Experts interviewed by the New York Times also said people may want to consider their plans before having another shot, timing the dose to maximize protection when, for example, they’re most exposed due to travel.
The only variable that would make a new booster more urgent for everyone would be a new rise or a new variant emerging. In that case, Sette said, the case of getting a fourth shot as soon as possible would be stronger.
“This can change on a dime,” he said.