• Ann Falco

Vaccine Hesitancy And The Impact On Herd Immunity


Currently, there are three COVID-19 vaccines authorized and recommended for use in the United States. These include the vaccines manufactured by Pfizer-BioNTech, Moderna, and Johnson & Johnson / Janssen. These vaccines have been determined to be safe and effective and help to reduce the risk of severe illness. However, there are still individuals that are reluctant to receive safe and recommended vaccines. As the country enters yet another wave of the COVID-19 pandemic due to the surges in variant cases, this reluctancy, known as “vaccine hesitancy”, becomes a growing concern.

According to researchers, vaccine hesitancy among young adults may delay efforts to achieve herd immunity. Herd immunity is a form of indirect protection from an infectious disease and occurs when a large portion of the population becomes immune to the disease, making the spread of disease from person to person unlikely. This occurs through vaccination or previous infections resulting in the presence of antibodies, thereby reducing the likelihood of infection for individuals who lack immunity. Often, a percentage of the population must be capable of getting a disease in order for it to spread. This is termed threshold proportion. If the proportion of the population that is immune to the disease is greater than the threshold, the spread of the disease will decline. This is known as the herd immunity threshold. However, the more contagious a disease is, the higher the percentage of the population that needs to be immune to the disease in order to stop the spread. This is very dangerous with a harmful and contagious virus such as the coronavirus, so scientists are relying heavily on the use of vaccines.


As explained by the Mayo Clinic, herd immunity can be reached when enough people in the population have recovered from COVID-19 and have developed protective antibodies against future infection. However, reaching herd immunity through vaccination can be difficult due to vaccine hesitancy. Many individuals may object to getting a COVID-19 vaccine because of religious concerns, fears about the possible risks and side effects, or skepticism about the benefits. If the proportion of vaccinated people in a community is below the herd immunity threshold, a contagious disease could continue to spread.

One study found that approximately one in four unvaccinated people aged 18 to 25 said that they would not get the COVID-19 vaccination, despite the fact that this demographic has been found to be more likely than other age groups to transmit the coronavirus. This reluctancy jeopardizes the health of older unvaccinated adults and facilitates the rise of virulent vaccine variants.

Additionally, data collected from 5,082 respondents in the Household Pulse Survey conducted by the U.S. Census Bureau were analyzed and found that 83 percent of this population reported that they had not been vaccinated, 10 percent said they definitely will not get the COVID-19 vaccine, and 14 percent said they probably will not. The study appeared on July 14, 2021, in the Journal of Adolescent Health.

Despite these results, the U.S. is currently making progress toward herd immunity through a combined approach of natural infection and vaccines. Studies show that the number of fully vaccinated adults continues to rise. In addition, more than 31 million people in the U.S. have had confirmed COVID-19 infections, although it’s not clear how long immunity lasts after infection.

Given these challenges, it is not completely clear if or when the U.S. will achieve full herd immunity. However, the FDA-authorized COVID-19 vaccines are highly effective at protecting against severe illness requiring hospitalization and death due to COVID-19. Additionally, prompt vaccinations could help limit the further development of virulent variants and infection rates among the vulnerable and unvaccinated.

Among the unvaccinated respondents who said they would definitely not or probably not get the vaccine; more than half said they were concerned about possible side effects. Many people plan to wait to see if the vaccine is safe. In these cases, it is important to provide clear and thorough information and details on the known side effects and risks associated with the vaccines. Researchers recommend that the concerns about vaccine safety and side effects be addressed through public education campaigns, social media platforms, and key influencers. These methods can be very effective and serve as great tools for education and awareness to help reduce vaccine hesitancy, especially in young adults.

The reasons for COVID-19 vaccine acceptance and hesitancy remain complex. As different COVID variants emerge and new vaccines are approved, it will be important to maintain a balance in communicating what is known and acknowledging the uncertainties that remain. As new data and information on COVID-19 becomes available to the public, researchers and drug manufacturers should be as forthcoming and transparent as possible. Together, this information can be used to encourage young adults to get vaccinated which will help reduce vaccine hesitancy and bring the U.S. closer to achieving herd immunity.


 

Speaking Plainly:

  • Vaccine hesitancy among young adults may delay efforts to achieve herd immunity.

  • Many individuals may object to getting a COVID-19 vaccine because of religious concerns, fears about the possible risks and side effects, or skepticism about the benefits.

  • Despite vaccine hesitancy in the age group of 18 to 25, the U.S. is currently making progress toward herd immunity through a combined approach of natural infection and vaccines. Studies show that the number of fully vaccinated adults continues to rise.

  • Concerns about vaccine safety and side effects should be addressed through public education campaigns, social media platforms, and key influencers.

  • New data on COVID-19, vaccines, and information from researchers and drug manufacturers could be used to help reduce vaccine hesitancy and bring the U.S. closer to herd immunity.