Dr. Mark Kortepeter, a physician and biodefense expert, discusses the possibility of Covid infection even after vaccination and explains why the pandemic isn’t over yet.
A lot has changed in the past few weeks, with mostly good news about Covid. Cases, hospitalizations, and deaths in the United States are falling. The U.S. has (so far) avoided a fourth wave, and the CDC has recently revised recommendations that allow for fully vaccinated people to “resume activities without wearing a mask or physically distancing,” except where required otherwise by laws and regulations.
The vaccines for Covid are highly effective in preventing disease, with some >90% effective, and around one third of the U.S. population has been vaccinated. Are we seeing the light at the end of the tunnel that we have all been waiting for? I like to think so, but not so fast. I am by nature a bit of a pessimist. And there are reasons to be cautious – for one thing, while the new vaccines have proven to be very effective, the risk of infection remains, however small.
Vaccines Are Not Perfect
As the U.S. rushes to open, I can’t help but think, despite the warmer weather, that we are bound to see at least some resurgence in Covid cases. I am not alone in this concern. Vaccines are not a complete panacea, and their protection can be overcome. If we consider the vaccines like a piece of body armor, visualize them more like chain mail rather than solid plates.
A vaccine that is 90% effective means, theoretically, that if 200 million people are vaccinated, around 20 million of them might still be infected and get sick. The vaccine’s actual effectiveness may vary depending on one’s underlying immune system and exposure risk. In addition, we don’t know the duration of protection or when a booster might be needed.
I started thinking about this issue recently, because I learned a friend and colleague was hospitalized for Covid. He was fully vaccinated only three months earlier, and he and his wife (also fully vaccinated) were both infected. Both had underlying illnesses, though, which may have reduced their response to the vaccine and made them more susceptible to infection, but many other people are in that same boat.
Covid Trends Are Shifting Positively, But ‘Breakthrough Infections’ Are Occurring
I had a call recently with colleagues across the U.S. who are taking care of Covid patients. The numbers of patients they have seen in their hospitals recently are coming down, but those numbers remain highly variable. They have noticed a general trend of fewer severe cases requiring admission to the intensive care unit; and have also noticed a shift from older to younger patients.
Generally, this sounds much better than what we were dealing with just a few months ago. Perhaps we have reached levels of vaccine immunity in the population to at least reduce the numbers, especially the numbers of people who need hospitalization or intensive care. We will see whether this trend continues as we move into the summer and businesses open across the U.S., as people travel, attend weddings, graduations, and other large gatherings.
However, one trend concerns me. My colleagues are seeing their fellow healthcare providers in the hospital getting Covid infections. These are individuals who have mostly been fully vaccinated. Sometimes they are being infected by their own household members. Usually, the cases have resulted in less severe illness, but not always.
The CDC noted that thus far it has received reports of vaccine breakthroughs from 46 states, with 1359 hospitalized or fatal cases. That’s a small number, compared with over 115 million people currently vaccinated, and breakthroughs are expected. In addition, as has been noted recently in the Seychelle islands, despite a highly vaccinated population, numbers of cases shot up after restrictions on tourism were relaxed. This data serves as a reminder that “even after widespread vaccinations, infections are unlikely to stop completely.” We are probably seeing just the tip of the iceberg and are undercounting the actual number of breakthroughs. Some of the people with post-vaccine infections won’t get tested, especially if the illness is mild.
Travel And New Variants May Drive Cases Back Up
There are two other important points to consider. I have travelled several times in the past month. I have yet to travel on a flight that was not jam packed. People are itching to get out of the house. But outside the U.S., there is still a huge number of Covid infections, and winter is coming to the Southern Hemisphere. We are a global community. Whatever happens halfway across the globe can impact us in the U.S. So, the more that people travel, the greater the chance for reintroduction of the infection, and for the opportunity to import new Covid variants into the U.S. These variants may in turn spread more efficiently and eventually reduce the effectiveness of our vaccines. Finally, in some states, 20% or more of adults express reluctance to get vaccinated. Having a significant chunk of the population still susceptible to infection will allow Covid to continue to circulate and make people sick.
The hope is that once you are vaccinated, you build up an immune response to fight the virus, so that even if you come into contact with it, you are protected from infection or have a reduced severity of illness. If the virus is circulating, though, you still have the opportunity to encounter it and possibly be infected – despite vaccination.
I am not trying to make you paranoid. There is much to be optimistic about. Instead, I like to promote awareness of the risk, not fear. So the lesson here? Vaccines are great – but they are not perfect.
Covid is still circulating. The bottom line is – do not go out of your way to tempt fate. Be smart about your activities. Consider your own risk-benefit calculation for whatever activities you do. Follow the CDC guidelines. Wear a mask when in confined spaces around others or when in potentially high-risk settings, especially indoors and on airplanes—especially if you are unvaccinated. If you have underlying illnesses that could potentially reduce how well the vaccines work for you, please continue to remain cautious.
Let’s see how the summer goes before we pop the champagne cork and declare victory over Covid.