Herd immunity for the coronavirus may be “wishful thinking,” according to Dr. Clay Ackerly.
Ackerly, a primary care physician who was a faculty member at Harvard Medical School, said he recently had a patient test positive for coronavirus several months after previously recovering from COVID-19. His 50-year-old patient not only caught COVID-19 a second time, but the doctor said that the latest infection was much worse than the initial illness.
“During his first infection, my patient experienced a mild cough and sore throat,” Ackerly explained in an opinion piece for Vox. “His second infection, in contrast, was marked by a high fever, shortness of breath, and hypoxia, resulting in multiple trips to the hospital.”
Ackerly noted that doctors in New York and New Jersey have also seen patients appear to be reinfected by the virus. The doctor explained that the patient had tested positive for COVID-19 and had then tested negative for the virus twice before testing positive once again within a span of three months.
“It is possible, but unlikely, that my patient had a single infection that lasted three months. Some Covid-19 patients (now dubbed ‘long haulers’) do appear to suffer persistent infections and symptoms,” he said. “My patient, however, cleared his infection — he had two negative PCR tests after his first infection — and felt healthy for nearly six weeks.”
Ackerly acknowledged that research on COVID-19 and subsequent immunity is slim because viral research takes time, and the scientific community has only had access to this virus for a handful of months. Ackerly warned that the suspected lack of immunity in some former patients could mean that herd immunity may not be attainable.
“Also troubling is that my patient’s case, and others like his, may dim the hope for natural herd immunity. Herd immunity depends on the theory that our immune systems, once exposed to a pathogen, will collectively protect us as a community from reinfection and further spread,” he said.
A recent study from the United Kingdom found that antibodies for the coronavirus, when present, have a short lifespan. The study from King’s College London found that patients who attained a “potent” level of antibodies shortly after recovering from the virus had lost enough antibodies to fall below the potency threshold within three weeks. Ackerly’s patient was not tested for antibodies after recovering from the virus the first time, but the patient was well beyond the three-week window after appearing to catch the virus a second time.
Dr. Katie Doores, who authored the study, told the Guardian that these findings could have major implications for future vaccinations against COVID-19.
“Infection tends to give you the best-case scenario for an antibody response, so if your infection is giving you antibody levels that wane in two to three months, the vaccine will potentially do the same thing,” Doores said. “People may need boosting and one shot might not be sufficient.”
