Coronavirus booster Q&A: Who should get one and why do we need them?

Congratulations: You’re now eligible to get a coronavirus booster shot.

Should you? Can you mix and match brands? And how well does this stave off the new variant?

The short answers are yes, yes and to be determined, per experts. Here are the details on that and more, compiled by the Herald with input from Dr. Robert Klugman, medical director of employee health at UMass Memorial Medical Center.

Who should get a booster shot?
Everyone 18 years and older is currently eligible for a booster. Older adults and people with certain medical conditions are at risk of waning immunity more than young, healthy individuals and can benefit from boosters. Primary vaccination starts to lose efficacy two to three months after the shots, according to Klugman.

For young, healthy adults, getting a booster is still important. Klugman highlighted three reasons to get a booster shot — protecting yourself, keeping your loved ones safe and getting the pandemic under control. The more people who are fully vaccinated and boosted, the less transmission will occur — and the fewer opportunities for potentially dangerous new mutations.

Which booster should I choose?
The Centers for Disease Control and Prevention allows for mixing and matching of booster doses. Some studies have shown mixing doses can be beneficial, especially for Johnson & Johnson recipients who boost with an mRNA vaccine.

Klugman said there is no harm in mixing and matching. In many circumstances, getting the same vaccine as the primary series is the way to go. However, if your local pharmacy doesn’t have that in stock, it is much better to mix vaccines than to wait.

When should I get my booster?
People who received a Pfizer or Moderna primary series can get a booster as soon as six months after their second shot and patients who received a J&J shot can get a booster as soon as two months afterwards.

Klugman said there is no harm in waiting a bit longer if needed, and there is no need to rush out and get a booster exactly six months or two months after your primary series. He cautioned against getting a booster earlier than the six month or two month threshold, as you may not reap the full immune benefits.

Why do I need a booster?
Coronavirus vaccine-granted immunity is not as strong in the face of the delta variant, and significant numbers of fully vaccinated people have been getting breakthrough cases as a result. Clinical trials show boosters increase antibody responses significantly, providing more protection against coronavirus. Klugman said by getting boosted, you can protect yourself, your community and help the country get ahead of the virus.

What side effects can I expect from a booster?
If you get the same type of vaccine as your primary series, you can expect similar side effects from the booster shot. If you mix and match, you may get more side effects, Klugman said. However, everybody is different and some patients may experience no side effects at all, while others may have injection site pain, fatigue, headaches or other mild symptoms that should be short term. There is nothing that can be done to prevent side effects, said Klugman, who recommended against taking pain relievers prior to a booster appointment as the effects of the medication could impact the vaccine.

Will I need to keep getting boosters in the future?
It is too soon to know whether more coronavirus boosters will be needed in the future, and it will depend on how the virus continues to mutate and spread. Getting many booster shots over time is not harmful and they don’t stay in the body, according to Klugman.

How does a booster shot work?
The immune system works in two ways, by producing antibodies and also T cells, which have a longer memory. The booster shot wakes up the immune system to create more antibodies that are ready to get to work should you be exposed to coronavirus, instead of fully relying on T cells which may have lost some memory over time.

Coronavirus boosters are the exact same shots as the primary series. Moderna’s booster is a half-sized dose while Pfizer and J&J boosters are the same size.

What about omicron?

The companies that produce vaccines have said they’re studying the efficacy of the existing vaccines and boosters on the newly named omicron variant, which has made headlines over the past few days. If necessary, the companies can retool vaccines within a few months to gear more toward the variant.

Experts say the emergence of the possibly more-contagious omicron variant makes getting boosters all the more important.