U.S. regulators on Tuesday approved another COVID-19 booster for people aged 50 and over, a step to provide extra protection for the most vulnerable if the coronavirus recovers.
The decision of the Food and Drug Administration opens a fourth dose of Pfizer or Moderna vaccines in this age group at least four months after their previous booster dose.
So far, the FDA has cleared the fourth installments only for people 12 years of age and older who have severely weakened immune systems.  The agency said this highly fragile team could also get an extra boost, a fifth shot.
The latest expansion, regardless of human health, allows an extra shot to millions more Americans – and the question is whether everyone who is eligible should rush in and get it.  The Centers for Disease Control and Prevention is expected to weigh.
Anyone eligible for a first boost that they have not yet received should do so, said FDA chief vaccine chief Dr. Peter Marks.  But the second boost is only for those at higher risk, because “current data suggests some reduction in protection” for them.
The move comes at a time of great uncertainty.  COVID-19 cases have dropped to low levels following the winter wave of the omicron superconducting variant.  Two doses of vaccine plus a booster still provide strong protection against serious illness and death, according to the CDC.
But an Omicron sibling is causing a worrying jump in infections in Europe – and spreading to the US – even when vaccination has stopped.  About two-thirds of Americans are fully vaccinated and half of those eligible for a first souvenir have not been vaccinated.
Pfizer had asked the FDA to make a fourth installment for people 65 and older, while Moderna asked for another installment for all adults “to give flexibility” to the government to decide who really needs it.  The FDA has set the age limit of 50 for both companies.  For immunosuppressed people, only the Pfizer vaccine can be used in people up to 12 years of age.  Moderna’s is for adults.
There is limited evidence to suggest how much benefit another amplifier might offer at this time.  The FDA made the decision without the input of its independent panel of experts who have struggled with how much data is needed to extend the shots.
“There may be a reason to fill the tanks a little” for the elderly and those suffering from other conditions, said University of Pennsylvania immunologist E. John Warry, who did not comment on the government’s decision.
But while encouraging older friends and relatives to follow the advice, 50-year-old Wherry – who is healthy, vaccinated and refreshed – does not intend to get a fourth vaccine right away.  With serious illness protection still strong, “I will wait until there is a need.”
None of the COVID-19 vaccines are as potent against the mutant micron as they were against previous versions of the virus.  Also, protection against milder infections naturally decreases over time.  But the immune system builds multiple layers of defense and the formula that prevents serious illness and death endures.
During the US micron wave, two doses were nearly 80% effective against the need for a respirator or death – and one booster boosted that protection to 94%, the CDC recently reported.  The effectiveness of the vaccine was lower – 74% – in immunocompromised individuals, the vast majority of whom had not received a third dose.
U.S. health officials also looked at Israel, which during the micron surge opened a fourth dose to people 60 and older, at least four months after their last shot.  The FDA said no new safety concerns were raised in the review of the 700,000 fourth installments.
Preliminary data posted online last week suggest some benefit: Israeli researchers counted 92 deaths among more than 328,000 people receiving the additional vaccine, compared with 232 deaths among the 234,000 who missed the fourth dose.
What is not at all clear is how long any additional benefit from another amplifier will last and, therefore, when you will get it.
“When ‘is a really difficult part.  “Ideally, we could use booster doses just before the surges, but we do not always know when this will happen,” said Dr William Moss, a vaccine specialist at the Johns Hopkins Bloomberg School of Public Health.
In addition, a longer interval between shots helps the immune system develop a stronger, more cross-defense.
“If you get a souvenir very close to each other, it does not hurt – you just are not going to benefit much from it,” Wherry said.
The latest boost may not be the last: Next week, the government will hold a public meeting to discuss whether everyone eventually needs a fourth dose, possibly in the fall, of the initial vaccine or an updated dose.
When it comes to vaccine updates, studies in individuals – for micron-targeted shots alone or in combination with the original vaccine – are ongoing.  The National Institutes of Health recently examined monkeys and found “no significant advantage” in using a micron-only amplifier.
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