Shouldn’t Natural Immunity Earn Some Freedom?

The antibodies from natural immunity may outlast those from the vaccine, research finds

People are being strongly encouraged to get vaccinated, even if they have natural immunity. ronstik/Shutterstock

Millions have rolled up their sleeves to take the COVID-19 vaccination because the jab promises protection against the notorious pathogen. However, millions more remain hesitant. Now, officials are pushing a new incentive: freedom.

A growing number of universities now require that students get vaccinated before they return to campus. Airlines and workplaces are devising apps that allow entry based on inoculation status. And several countries are either set to unveil, or have already rolled out, a vaccine passport program. Details in each system may vary, but they all involve lifting restrictions for those who take the COVID-19 vaccine, and maintaining restrictions for those who haven’t.

Most governments haven’t tried to mandate the vaccine—a gene therapy released under emergency use authorization in the United States that is still undergoing clinical trials. And even as they promote the idea of vaccine passports, officials maintain that the decision to get the shot is still a matter of personal choice. But, after a year of social restrictions, the promise of any measure of freedom certainly makes taking the jab a bit more tempting.

Critics call such programs manipulative and discriminatory. But supporters say these measures are a vital step toward easing the world safely back to normalcy.

On April 2, the U.S. Centers for Disease Control and Prevention (CDC) announced that fully vaccinated individuals (those who took their last recommended dosage more than two weeks ago) were permitted to freely travel by bus, train, or plane anywhere in the United States, provided they remain masked during their trip. Everyone else is still urged to get tested before they depart, and quarantine when they return.

“Vaccines can help us return to the things we love about life, so we encourage every American to get vaccinated as soon as they have the opportunity,” CDC Director Dr. Rochelle Walensky said in the statement.

The reasoning behind these vaccine-for-freedom programs is that vaccinated individuals are less likely to spread or contract the disease, and therefore deserve to have less restrictions than those at greater risk of transmitting a potentially deadly virus.

Community immunity is the goal, and health officials say the vaccinated earn their freedom by contributing to this goal through their antibodies. The presence of these immune cells are proof that vaccinated individuals possess protection that the unvaccinated do not.

But vaccination isn’t the only road to antibody protection. Just like with other viral infections, people who catch COVID-19 can develop some immunity to the disease. And when you consider the number of people who have contracted COVID-19 and recovered, many have likely earned their antibodies naturally.

So if the goal is disease defense, doesn’t natural immunity deserve a pass, too?

Drugmakers point to evidence of the antibodies produced in subjects who’ve taken their jabs. In April, Pfizer announced results of a phase 3 clinical trial showing that its vaccine provided more than 91 percent protection for at least six months after the second dose.

But natural immunity against COVID-19 has demonstrated promise as well.

According to research funded by the National Institutes of Health (NIH) and published in January in the journal Science, the immune systems of more than 95 percent of people who recovered from COVID-19 had “durable memories of the virus up to eight months after infection.”

It was clear in vaccine trials that natural immunity was a force to be reckoned with. Drugmaker Merck gave up on both of the vaccines it developed last year to guard against COVID-19. On Jan. 25, Merck researchers announced their decision after they discovered the vaccines offered less protection than just contracting the virus itself and developing antibodies naturally.

Whether or not you recovered from COVID-19, health officials want everyone to take the shot. But the benefit this treatment offers those who have already created their own immunity isn’t clear. In December 2020, the CDC stated that the Pfizer vaccine demonstrated benefit for those with evidence of prior COVID-19 infection, but the health agency later admitted the claim was made in error.

Proving Immunity

There has been talk of granting immunity certificates to those who recovered from COVID-19 that would function in much the same way that vaccine passports work. However, when it comes to handing out freedom to the naturally immune folks, there are concerns to consider: How strong is their protection and how long will it last?

These concerns are discussed in a February report from The Royal Society in the UK. The report points to qualitative studies that suggest that antibodies generated by natural infection provide “strong protection against illness”—between 70 and 90 percent efficacy for at least six months. However, researchers are concerned that natural immunity may also be less effective in reducing infectiousness and transmission, particularly against asymptomatic infection.

Another problem is that there is no standard to measure natural antibody protection.

“With regard to developing a satisfactory passporting test, no standard antibody assay yet exists and there are no validated antibody concentrations that correlate with or signify protection, either against illness or infectivity,” the report stated.

The issues of testing and standards for antibody levels were also discussed in a 2020 report from the World Health Organization examining the ethical considerations of immunity passports. Not only have these important markers not been scientifically established, but, more importantly, there are several cases of people who catch COVID-19, recover, and then catch it again.

“As such, the World Health Organization (WHO) has advised against the use of immunity certificates at this time as they have the potential to increase the risk of continued transmission,” the report stated.

To be fair, the longevity of protection the vaccine offers has also proven unreliable. On April 5, The Detroit News reported that as many as 246 Michigan residents considered fully vaccinated against COVID-19 were later diagnosed with the virus. Three of this group died following their diagnosis.

Cases were reported between Jan. 1 and March 31. A spokeswoman for the Michigan Department of Health and Human Services said the cases are undergoing further review. Similar reports of so-called “breakthrough” cases have appeared in Washington State, Hawaii, New York, and other states.

Conditions for Freedom

The WHO report lists three conditions that would need to be met for immunity certification to be a reasonable policy approach. Two require scientists to establish antibody standards.

First, what are reliable indicators for protection? And second, since declining immunity is common in coronavirus infections, a minimum length of immunity must be established.  This duration must be “monitored over time so as to understand whether and when certificate holders need to reassess their immunity status and, possibly, renew their certificate.”

The third condition requires the availability of accurate tests to identify immune individuals. However, the technology currently available is time-consuming, and requires expensive lab analysis, making widespread antibody testing not so feasible.

But researchers are already developing solutions to meet these challenges. Earlier this month, a group of Canadian scientists announced a new, inexpensive test that can detect COVID-19 antibodies in less than an hour using one drop of blood. It utilizes a bioluminescent enzyme called luciferase that gives fireflies their glow. The test has proven to be highly accurate. It doesn’t require a lab and is easy to read. The more antibodies found, the brighter the test card glows.

Of course, none of this will be necessary in places that don’t require vaccines for freedom, and so far at least three states have executive orders that forbid these programs. In a March 29 press conference, Florida Gov. Ron DeSantis said that it’s “completely unacceptable” for the government or the private sector to impose that people show proof of vaccine simply to participate in normal society.

“I think this is something that has huge privacy implications and is not necessary to do,” DeSantis said. “[Vaccination] is something we want available for all, but mandated for none.”