“Hidden Gaps: Study Reveals Limited Access to Pneumococcal and Flu Vaccines at US Travel Clinics”

After nearly 117,000 pre-travel health consultations spanning a decade across 31 locations in the US, it was found that 68% of qualified travelers were not provided the pneumococcal vaccine, and 15% did not receive the flu vaccine—even during their destination’s flu season, as reported by researchers from Harvard Medical School and their collaborators yesterday in Open Forum Infectious Diseases.

The research team examined online surveys filled out by patients from the Global Travel Epidemiology Network and the providers during their pre-travel consultations. They also constructed multivariable logistic regression models to pinpoint factors associated with receiving the vaccinations from July 2012 to June 2022.

Pre-travel health consultations are concentrated on advising and ensuring that travelers are current with their routine vaccinations. The average age of the assessed travelers was 38 years, with 57% being female, and Africa was the most frequently chosen destination (42%). A majority (59%) intended to travel for a minimum of 2 weeks.

“Infections caused by Streptococcus pneumoniae and influenza viruses are preventable by vaccines and result in significant morbidity and mortality,” the researchers indicated. “Influenza poses a leading travel-related risk, with an estimated incidence of about 1% per month of travel.”

Obstacles to vaccination

During the 116,865 pre-travel appointments, 25% of travelers were qualified for the pneumococcal vaccine, yet only 68% of those eligible were offered the vaccination. The most frequent reason given for the absence of the pneumococcal vaccine offer was the provider’s belief that it was not necessary based on the traveler’s planned itinerary.

It is important to note that influenza vaccines expire each year on June 30th and are typically not accessible in the United States from July to late August.

“Although the pneumococcal vaccine is not specifically a travel-related vaccine, these travel clinic interactions signify missed chances for vaccination, either during the encounter or through referrals to other providers,” the researchers stated.

Challenges in obtaining pneumococcal vaccination could stem from the lack of insurance coverage for non-travel vaccines at pre-travel health consultations or insufficient vaccine supplies in certain travel clinics, they noted.

Among the 48% of travelers qualified for the flu vaccine, 15% were not offered it, and an additional 30% opted out. For 14% of those eligible, the flu vaccine was not available. Aside from vaccine refusal, other obstacles included a lack of availability (20%) and the provider not deeming the vaccine appropriate for the itinerary (19%).

“These two challenges were particularly prevalent during travel visits occurring between April and September,” the study authors remarked. “It is crucial to highlight that influenza vaccines expire on June 30th each year and are generally unavailable in the United States from July to late August.”

Travelers were less inclined to receive vaccination if they were seen at medical facilities outside the Northeast (Midwest odds ratio [OR], 0.32; South OR, 0.53; West OR, 0.33) or if they attended non-academic centers (OR, 0.52). Conversely, travelers aged 65 years and above were more likely to be vaccinated (OR, 6.07), as were those with one or more underlying health conditions (OR, 1.61).

Enhancing awareness of global flu epidemiology and seasonality

Of the 56,150 travelers eligible for the flu vaccine, 59% were traveling to a locale during its flu season.

Incorporating destination-specific influenza risk in resources commonly referenced by providers and travelers, like the CDC Traveler’s Health website, might serve as an additional means of boosting awareness.

“Enhancing understanding of global influenza transmission trends and improving access to routine vaccinations during the pre-travel consultation could improve vaccination rates for respiratory pathogens among departing U.S. international travelers,” the study authors concluded. “Moreover, numerous destinations, particularly Kenya, Malaysia, and Singapore, among other tropical regions, have year-round influenza transmission.”

They suggested encouraging providers to utilize resources on the global epidemiology and seasonality of flu, such as those provided by the World Health Organization. “Incorporating destination-specific influenza risk in frequently consulted resources by providers and travelers, including the CDC Traveler’s Health website, may be another effective method to increase awareness,” they wrote.

Making available a Northern Hemisphere flu vaccine at travel clinics during the summer months in the US could also be advantageous. “One potential approach might involve allowing travel clinics to use influenza vaccines past the June 30th expiration date for eligible travelers whose itinerary includes areas with ongoing transmission, until the vaccines for the new season are ready; however, this would necessitate regulatory changes, as providers are not permitted to administer expired vaccines,” the researchers wrote.

“An alternative, albeit more complicated, solution would be to employ Southern Hemisphere influenza vaccines as travel vaccines for travelers crossing hemispheres, which would also account for the likelihood that travelers to the Southern Hemisphere might encounter influenza viruses not contained in the Northern Hemisphere influenza vaccine,” they added.