Basic vaccine questions still go unanswered despite rollout
Data lacking on how long protection lasts, what kind of immunity occurs
Whoops of celebration, crackling applause and tears of joy erupted as the first health care workers were jabbed with the coronavirus vaccine last week, kicking off the largest mass vaccination campaign in history.
But after they get their second dose, will they have to roll up their sleeves all over again in six months or a year? Will you?
In this unprecedented, worldwide, real-time experiment, the answers to many questions remain shrouded in mystery. But scientists have been scrutinizing the novel coronavirus for nearly a year, and their understanding of its wily ways grows every day.
What kind of immunity will these shots provide, and how long will it last? When might we reach “herd immunity,” when life can return to normal? Will we ultimately mandate vaccination of our citizens to help us get there faster?
Hope, fear and misinformation are in plentiful supply as the “light at the end of this long, dark tunnel” glistens. So here’s the latest on COVID-19 immunity — and the law regarding mandatory
vaccinations — following the U. S. Food & Drug Administration’s emergency approval of Moderna’s vaccine Friday and as more shipments of Pfizer-BioNTech’s vaccine wend their way to California.
But a word of caution. “No vaccine protects 100% of the people 100% of the time,” said David D. Lo, distinguished professor of biomedical sciences at UC Riverside. “That’s why people talk about this larger question of ‘ herd immunity.’ Some people won’t be able to take the vaccine because of allergies or other issues. How do you protect them? You make sure everyone else is protected.”
Timothy Brewer, professor of epidemiology at UCLA’s Fielding School of Public Health and a member of the infectious diseases division at the David Geffen School of Medicine, agrees.
“This idea about reaching herd immunity through natural infection — there’s no such thing,” Brewer said. “Smallpox never went away until we had a smallpox vaccine. Polio never went away until we had a polio vaccine. Herd immunity is stopping transmission, and that has never happened without a vaccine.”
How long does immunity last?
Earlier in the pandemic, studies found that some recovered COVID-19 patients experienced precipitous drops in disease-fighting antibodies just months after infection. The milder the case, it seemed, the fewer the remaining antibodies. In some people, no antibodies were detectable at all.
Combined with a handful of confirmed reports of people getting COVID-19 a second time, there was alarm.
But more recent studies are sharpening the picture. Antibodies aren’t the only arrow in the immune system’s quiver: There are also warrior T cells and B cells that appear ready to resume the battle if and when the coronavirus is detected again. A recent study found that, eight months after infection, most recovered patients had enough immune cells to fend off the virus and prevent illness, suggesting immunity could last a year or more.
“T he general feeling is, this means there’s at least short-term immunity against repeat, severe disease,” said Marisa Holubar, infectious disease physician at Stanford Health Care.
And even if reinfection is “a thing,” it appears to be much less severe the second time people get the virus, said Andrew Noymer, an epidemiologist and population health scientist at UC Irvine. “But will the vaccine protection be comparable to having survived natural infection? Nobody knows yet. It may even be superior.”
The immune response to natural infection appears dependent on how much virus was encountered — a robust response from surviving a large exposure, a weaker response from surviving a small exposure. Vaccines eliminate that wild card: They’re calibrated to invoke a standard, robust, immune response. That’s why the U.S. Centers for Disease Control and Prevention recommends that survivors of natural infection get vaccinated.
And even if immunity only lasts a few months, that’s not so bad: People would simply require more frequent booster shots.
“I get the flu shot every year, tetanus every 10 years,” Lo said. “So this tells you the immune system does what it can, but the reason we have modern medicine is to augment where nature isn’t always up to snuff.”
Will I be forced to get vaccinated?
No one is going to tackle you and plunge a needle into your arm against your will — but there are other ways of inspiring compliance.
“The federal government actually has limited power here, but states have broader authority to act on public health,” said Dorit Rubinstein Reiss, professor at UC Hastings College of Law in San Francisco.
The guiding case law is Jacobson v. Massachusetts, a 1905 Supreme Court decision that’s the foundation of the country’s public health laws, she said. An outbreak of deadly smallpox wracked the city of Cambridge in 1902, and its Board of Health ordered the vaccination of all residents. Henning Jacobson, a pastor, refused. He had suffered a bad reaction to a smallpox vaccine in his native Sweden and argued that requiring him to be vaccinated again was “unreasonable, arbitrary and oppressive” and an invasion of his liberty.
The U.S. Supreme Court did not agree. “In every well ordered society charged with the duty of conserving the safety of its members the rights of the individual in respect of his liberty may at times, under the pressure of great dangers, be subjected to such restraint … as the safety of the general public may demand,” it said. Today’s courts may need to decide whether that logic still holds.
California has another tool. The Legislature last year passed a law empowering local health officers “to take any action the local health officer deems necessary” to control the spread of communicable disease. That could include vaccine mandates on the county or city level, Reiss said, and will likely play out in court as well.
Vaccines really can’t be mandated before formal FDA approval — right now, they’re available through emergency use authorization. But once they’re approved for regular use, “employers will be a lot less antsy about mandating it. ‘If you want to work here, you have to get your coronavirus shot,’ ” Noymer said.
Employers have broad rights and responsibilities to protect worker health, so vaccination could well be a part of that as long as reasonable accommodations are made for disabilities and religious beliefs, Reiss said. It could be required for attending school as well, or for air travel.
Folks may simply find it’s hard to do the things they want to do without rolling up their sleeves.
What if I still say no?
A new survey by the nonprofit Kaiser Family Foundation found that 71% of people would definitely or probably get a COVID-19 vaccine if it were safe and free. Would that be enough to stop the virus in its tracks?
It all depends on the transmissibility of the pathogen, UCLA’s Brewer said. Measles is so contagious that some 95% of people need to be vaccinated to shut down transmission; even small pockets of unvaccinated people are enough to spark outbreaks, as record-setting case numbers in recent years have illustrated.
COVID-19 may not be as contagious as the measles. Experts estimate that 6080% of adults will need to be jabbed.
“The more the better,” said Stanford’s Holubar.
A recent study found that vaccines with high efficacy, such as Pfizer’s and Moderna’s, could vastly reduce hospitalization and death — by more than 85% — even if only adults get vaccinated. But if 40% of the population refuses, “vaccination is unlikely to completely eliminate the need for nonpharmaceutical interventions” such as masks and physical distancing.
How long will the vaccinated keep wearing masks to protect those who refuse?
“There’s the question of when you say, ‘ You’re on your own, buddy,’ ” Noymer said. “Assuming the vaccine works and is durable, then it’s a fairly open question what our duty is to people who are refusing.”