COVID Reinfection Study Shows Why Aged Grown-ups Need to Get Vaccinated
Natural Immunity After COVID-19 If you’ve been infected with COVID-19, your body may have built some natural immunity to the virus without vaccination. But experts have found that this is not always the case.
New research published in The Lancet found that natural immunity after recovering from COVID-19 protected individuals from reinfection for at least six months. However, this effect was less robust in adults over the age of 65.
The study revealed that only 47% of adults over 65 were protected against reinfection compared to about 80% of younger adults.
SARS-CoV-2 Reinfection Rates
SARS-CoV-2 Reinfection Rates Researchers tracked reinfection rates during the second surge of COVID-19 from September 1 to December 31, 2020. Data was collected from the Danish Microbiology database, analyzing PCR results from throat swabs taken during the first and second surges.
The study involved 339,000 individuals tested in both surges. About 2.11% tested positive during the first wave, and 0.65% were reinfected in the second. Around 3.3% of individuals who tested negative in the first surge tested positive later.
Researchers calculated that 80% to 83% of participants were protected from reinfection. Older adults (65 years and older) had lower protection at 47% compared to younger adults. No significant waning of immunity was observed six months after infection.
Reinfection Risks for High-Risk Groups
Reinfection Risks for High-Risk Groups Beyond the current study, other research suggests that immunocompromised individuals may also face higher reinfection risks.
What This Means For You Increasing vaccination rates across the country brings hope for a return to normalcy. However, achieving herd immunity will take time. With the rise of COVID-19 variants and the possibility of reinfection, it is vital to follow CDC guidelines, including mask-wearing and social distancing when possible.
Can Vaccines Protect Against Reinfection?
Can Vaccines Protect Against Reinfection? MarkAlain Déry, DO, MPH, FACOI, an epidemiologist and medical director at Access Health Louisiana, notes that approved vaccines were designed to protect against the original COVID-19 strain. Reinfection remains rare but becomes more plausible with variants.
Lancet study
The study in The Lancet did not address variants of concern, such as those from the UK (B.1.1.7), Brazil (P.1), and South Africa (B.1.351). These variants have mutations that enable faster transmission and immune evasion.
Fortunately, current research suggests vaccines effectively combat the B.1.1.7 variant. However, there is limited data on vaccine efficacy against B.1.351 and P.1. Cases of massive reinfections with these variants have been reported. For instance, in Manaus, Brazil, a resurgence of COVID-19 cases included 42% linked to the P.1 variant.
Vaccination Is Your Best Protection
Vaccination Is Your Best Protection While more information is needed about variants, vaccines remain the best defense against severe illness and reinfection.
A February 2021 preprint study in medRxiv estimates that increasing vaccination efforts and implementing partial lockdowns can help limit the spread of dominant variants.
Key Takeaway
- Adults 65 years and older face a higher risk of COVID-19 reinfection without vaccination.
- Even if you’ve previously been infected, getting vaccinated is the best way to ensure immunity.
- Vaccines are effective against reinfection, but emerging COVID-19 variants may complicate the situation.