Vaccines to prevent common and serious infectious diseases have had a greater impact on improving human health than any other medical advance of the 20th century, surpassing even sanitation and potable water. From the global eradication of smallpox in 1980 to the unprecedented development of effective and safe mRNA vaccines for COVID-19, vaccinations have played crucial roles in preventing millions of premature deaths and hospitalizations in adults and children.

These monumental efforts have involved coordinated local, regional, national and international organizations and dedicated clinical and public health professionals. Unfortunately, over the past decade,  decreasing vaccination rates now threaten the huge beneficial impacts of vaccinations in the United States and globally.

In the departments of medicine, and population health and social medicine, health care providers and public health officials should remain cognizant that increasing vaccination rates are essential but not sufficient. Surveillance-containment entails rapid detection and reporting of cases with prompt immunization of household members and close contacts of confirmed cases, combined with judicious use of isolation, prompt antiviral or antibiotic medications, social distancing, respiratory etiquette; home or large-scale quarantines; and masking. The continuing and expanded efforts of U.S. health care providers are vital to these successes.

The authors note that health care providers in the U.S. also face major challenges in achieving high vaccination rates against COVID-19, respiratory syncytial virus (RSV) and influenza, which confers particularly high risks among the elderly and immunocompromised patients. They caution about potential concerns relating to  the recent emergence of a highly virulent strain of influenza (H5N1) in China. 

“The pneumococcal vaccine has also been shown to be safe and effective in randomized trials for patients aged 18 to 79, including those over 80, making it particularly beneficial for the elderly, immunocompromised individuals, and those at high risk for pneumonia,” said Hennekens. “Furthermore, Herpes zoster, or shingles, affects 1 in 3 people over 65 and is caused by the reactivation of the varicella zoster virus from past chickenpox infections. It can lead to debilitating complications and is especially concerning for immunocompromised patients. The shingles vaccine is safe, effective and FDA-approved for individuals aged 50 and older.”

Although it was eliminated in 2000, the authors also discuss the clinical and public health challenges of measles in the U.S. and worldwide. Recent outbreaks in areas with low vaccination rates, exacerbated by more recent vaccine hesitancy, have led to a loss of herd immunity. By July 2023, 116 out of 195 countries reported lower measles vaccination rates. The World Health Organization (WHO) estimates that vaccinations since 1974 have prevented about 154 million premature deaths, with 101 million of those being infants.

Maintaining herd immunity is crucial to prevent future measles outbreaks and related deaths. Lastly, in August, the WHO declared mpox a global public health emergency. Mpox, a variant of smallpox, was largely controlled by smallpox vaccinations, which have declined since its eradication in 1980.

“The emergence of new variants, particularly clade Ib, poses increased mortality risks,” said Hennekens. “A recently developed vaccine has been effective in limiting spread, particularly in high-risk areas like sub-Saharan Africa. However, global vaccination efforts face special challenges, including limited supplies and inadequate delivery to vulnerable populations.”

(Newswise/NK)