Fact vs. Fiction: “Breakthrough” Cases and Hospitalization Rates
COVID vaccines effectively lower your risk of infection, hospitalization, and death. However, it is still possible to be fully vaccinated and come down with COVID-19, also known as a breakthrough infection. This information can help you separate facts from fiction regarding breakthrough infections and hospitalization rates.
Current Facts about COVID-19 Vaccination
According to the Centers for Disease Control and Prevention (CDC), people aged five years and older can receive two injections of the Pfizer and Moderna vaccine or one injection of the Johnson & Johnson COVID vaccine. A CDC study found that people who were unvaccinated and had previous COVID-like symptoms were five times as likely to have COVID-19.
Additional research suggests that vaccinated individuals who contract COVID need six fewer days to recover from being sick, have 40 percent lower viral loads, and about half the infection longevity. Also, fully vaccinated people tend to have a reduced risk of some hospitalizations, even after having a previous infection.
People who are moderately or severely immunocompromised may not get complete protection from vaccination and should get an additional vaccine dose and a booster. Because of the added risk, they should take the same precautions recommended for unvaccinated individuals.
What Is a “Breakthrough” Infection?
A vaccine breakthrough infection occurs when a fully vaccinated person becomes infected with COVID-19. Because no vaccination is 100 percent effective, this occurrence is not unusual or unexpected. In a study in Washington state of over 4 million vaccinated individuals, about 1 in 5,000 people had a breakthrough infection between January 17-August 21, 2021. Some geographic locations have seen that rate jump to 1 out of 100.
Tracking throughout the rest of the country can be more challenging. The United States only keeps a record of breakthrough COVID-19 cases that get hospitalization. Countries with national healthcare systems that track individual patient data generally have more accurate estimations of infection rates.
Nevertheless, breakthrough infections are increasing in the U.S. and elsewhere. As recently as December 2021, many new cases have been due to Omicron, recently surpassing Delta as the leading variant in the U.S. This shift could be due to the lowered efficacy of vaccines against Omicron compared to Delta.
If you experience a breakthrough infection, being fully vaccinated and boosted means you will have a decreased chance of suffering severe illness. You will also be less likely to have “long-haul COVID,” characterized by lingering symptoms after acute phases have ceased. Also, symptoms associated with breakthrough COVID-19 infections are generally mild compared to unvaccinated patients. However, individuals living with HIV, organ transplants, some cancers, and certain chronic conditions should receive an additional vaccine dose 28 days after their second injection or booster.
Being fully vaccinated can make a difference in breakthrough hospitalizations, most of which tend to occur among people aged 65 and over. In contrast, most people unvaccinated and hospitalized are usually aged 18-64. Also, breakthrough hospitalizations tend to involve fewer patients with chronic respiratory conditions, suggesting that most of these individuals needed hospitalization for non-COVID reasons.
As with any person getting COVID, people experiencing breakthrough infections can spread the virus to others, possibly leading some people to question whether vaccines are worth the time and effort. However, vaccination is the best way to combat the emergence of each new variant that surfaces. Vaccination helps slow down the spread of the virus, hindering its ability to mutate and travel from person to person.
Monitoring of COVID-19 and Hospitalizations
One of the primary reasons scientists keep seeing breakthrough cases is that new variants tend to get more robust to protective measures like vaccines. The coronavirus mutates more often than the flu virus. It results in numerous strains that researchers, policy-makers, and public health agencies need to track painstakingly, especially to anticipate surges in hospitalization rates.
Scientists and public health experts still have much to learn about breakthrough infections. The CDC continually collects data and monitors vaccine effectiveness. Also, tracking hospitalization rates can shed light on vaccine effectiveness against emerging variants.
CDC’s Coronavirus Disease 2019 (COVID-19)-Associated Hospitalization Surveillance Network (COVID-NET) collects and maintains data on hospitalizations related to COVID infection. This database includes cases that test positive by healthcare professionals and result in hospitalization, including breakthroughs. COVID-NET covers over 250 hospitals in 14 U.S. states, about 10 percent of the U.S. population.
COVID-NET monitoring can reveal a great deal about the impact of vaccinations on hospitalization prevention. For example, among adults between 65-74 years old, the effectiveness of full vaccination in preventing hospitalization was 96 percent for the Pfizer-BioNTech and Moderna vaccines and 84 percent for the Johnson & Johnson shot.
Research and materials for this article were compiled, written, and distributed on behalf of the National Public Health Information Coalition. The views and opinions expressed in this blog are those of the various authors and do not necessarily reflect the official policy or position of the National Public Health Information Coalition or its members.