Life Course Vaccination: Protection Across Generations

Many countries that were early to introduce MCV2 have been able to maintain or even increase coverage following COVID-19-related disruptions. For example, Zambia was able to increase national MCV2 coverage from 65% in 2018 to 77% in 2024. Further, several countries that have introduced MCV2 in the past few years have steadily increased coverage. Longstanding measles immunity gaps in the Democratic Republic of the Congo had previously contributed to increasing numbers of measles cases and frequent outbreaks, but after introducing MCV2 nationally in 2022, the country managed to achieve 51% coverage in 2024. 

Rotavirus

Over the past two decades, rotavirus vaccines have helped reduce the global burden of severe rotavirus gastroenteritis [2], which can lead to hospitalization or even death. As of April 2026, 140 countries have introduced rotavirus vaccines into their national immunization programs, including 46 Gavi-eligible countries. This number is up from 120 countries just five years ago, with recent introductions in Nigeria, Chad, South Sudan, and Cambodia, among other countries. Six additional Gavi-eligible countries are planning to introduce rotavirus vaccines into their national immunization programs, and three countries have introduced subnationally. 

Of the countries that have not yet introduced rotavirus vaccination, several are in sub-Saharan Africa and South and South-eastern Asia, including Guinea, Central African Republic, Papua New Guinea, and Bangladesh, among others. As these regions are home to a large number of rotavirus deaths in children under 5 years [3], future efforts to advocate for rotavirus vaccine introduction should focus on these countries to have the biggest impact on child health.

PCV

Pneumococcal conjugate vaccines (PCVs) have been highly effective at preventing childhood pneumococcal disease, an important cause of mortality among children under 5 years. As of April 2026, 177 (91%) countries have introduced PCVs, including 50 Gavi-eligible countries. An additional eight countries are planning introduction of PCVs into their national immunization programs. WHO recommends that countries achieve high coverage of three doses of PCVs by using either three primary doses without a booster dose (3+0) or two primary doses with one booster dose (2+1). Countries with mature PCV programs and adequate levels of population herd immunity can consider a reduced dosing schedule of one primary dose with one booster dose (1+1) to lower costs and give fewer injections, although this approach requires high vaccination coverage and close monitoring to ensure adequate protection. 

Of countries that have introduced PCVs, about half of countries (85) use a 2+1 schedule, followed closely by those using a 3+0 schedule (69 countries). Just one country (United Kingdom) currently uses a 1+1 schedule. Maintaining high coverage of PCVs regardless of dosing schedule is essential for preventing childhood pneumonia deaths.

Vaccination in Adolescence

As children get older, there is generally less focus on their immunization needs and fewer touchpoints with the health system. However, vaccination remains a critical intervention among this population to combat the waning immunity to childhood vaccines as well as to provide protection against diseases that are unique to adolescents (such as invasive meningococcal disease, which adolescents are at increased risk for due to close contacts at school and other social behaviors) [4]. Human papillomavirus (HPV) vaccines are also recommended for this age group before they become sexually active to protect against cervical cancer and other cancers later in life.

HPV

Although HPV vaccine introduction was originally limited to high-income countries, 161 countries of all income levels (including 36 Gavi-eligible countries) have introduced universal HPV vaccination as of April 2026, with another 19 countries planning introduction. These introductions have been made possible largely by the adoption of a single-dose schedule, which has been found to provide comparable protection to a multi-dose schedule while drastically reducing the cost per adolescent [5]. As of April 2026, more than half of countries (and 92% of Gavi-eligible countries) that include HPV vaccines in their national immunization programs have adopted a single-dose schedule. Of the 33 countries that have introduced HPV vaccination since the WHO included a single-dose schedule as an off-label alternative in December 2022, more than two-thirds (23) have introduced using a single-dose schedule. 

Approximately 45% of countries that have introduced HPV vaccines use a two-dose schedule, and just two countries continue to use a three-dose schedule. As evidence continues to demonstrate the non-inferiority offered by a single dose of HPV vaccine [6], more countries are likely to adopt this strategy, allowing them to reach more adolescents with fewer resources.