MEASLES: Lessons from COVID-19 to improve vaccination coverage
A recent study which sought to understand the trend of measles in Tanzania found a surge of confirmed cases in 2022 and disruption of vaccine coverage caused by the COVID-19 pandemic in 2019.
From January 2018 to December 2022, Tanzania reported 12,253 rash and fever cases, with 19.0% (2,340 cases) confirmed as measles. The majority were in the 1-4 years age group. The World Health Organization (WHO) officially confirmed a measles outbreak in July 2022, with more transmissions observed throughout the year.
In this study, published on the International Journal of Infectious Diseases, to which Ifakara’s Farida Hassan had contributed to, the scientists describe the trend of measles in Tanzania over a five-year period from 2018-2022.
In conclusion, the scientists advocate enhanced surveillance, routine immunization, and targeted strategies to attain the necessary immunity levels for effectively interrupting measles outbreaks.
What is measles?
Measles is a highly contagious disease caused by a virus, spreading easily when an infected person breathes, coughs or sneezes, it may result in severe complications, and even death and is most common in children.
Therefore, the WHO recommends that Children should receive two doses of the vaccine to ensure they are immune, Measles-containing-vaccine first-dose (MCV1) and MCV2. More on measles
Measles in Tanzania
The scientists emphasize that maintaining a 95% vaccine coverage can prevent measles. Tanzania initiated vaccination campaigns in 1999, reaching over 90% coverage by 2019. However, 2021 WHO/UNICEF Estimates of National Immunization Coverage (WUENIC) reveals a decline to “76% and 62% for the first and second doses of measles-containing vaccine, respectively, leaving an estimated 4 million susceptible children…” scientists say.
Effects of the COVID-19 pandemic
Despite immunization performance returning to pre-COVID-19 levels in 2022, the immunity gap caused by the pandemic led to increased measles transmission in Tanzania. The scientists say, "...the country faced measles outbreaks in all 26 regions in Tanzania mainland and 2 regions from Zanzibar Island.”
Scientists stressed the negative impact of COVID-19 by stating “immunization activities [were affected] due to the cancellation of mobile and outreach services, resulting in suboptimal surveillance performance."
Additionally, the COVID-19 pandemic resulted in flight cancellations, disrupting the supply of vaccines. Similar challenges have been reported in other countries, including western Uganda and the Democratic Republic of the Congo (DRC), despite having well-established surveillance systems and vaccination programs for children under five years of age.
Scientists are recommending targeted strategies to address the challenge of measles in Tanzania. Scientists urge that targeted strategies are required to attain equal to or greater than ≥95% coverage for both measles-containing vaccines to be able to interrupt measles transmission.
They add: “monitoring vaccine quality and storage to ensure efficacy and surveillance system to ensure timely detection and reporting.”
The study, spearheaded by Fausta Michael of the Immunization and Vaccine Development Program, Ministry of Health, Tanzania, enlisted the participation of Farida Hassan from Ifakara, alongside Delphinus Mujuni, Andrew Bahati, Pricillah Kinyunyi, Furaha Kyesi, Florian Tinuga, Dhamira Mongi, Bonaventura Muhindi, Joseph Mdachi, Richard Magodi, Mwendwa Mwenesi, Honest Nyaki, Medard Beyanga, Betina Katembo, Kelvin Tenga, Magdalena Kasya, and Richard Kasonogo from the Ministry of Health, Tanzania.
Additional contributors included Mariam M. Mirambo and Stephen E. Mshana from Weill Bugando School of Medicine, Gerald Misinzo from SACIDS Foundation for One Health, Omary Minzi and Elangiringa Kaale from MUHAS, Florence S Kalabamu from Hubert Kairuki Memorial University, Elias Nyanda from the National Institute for Medical Research in Mbeya, Mary Mwanyika-Sando from Africa Academy for Public Health, Daniel Ndiyo from Government Chemist Laboratory Authority, Abbas Ismail from the University of Dodoma, John Chai from the Judiciary of Tanzania, Abdul Salehe from the Ministry of Health in Zanzibar, and Willliam Mwengee from the World Health Organization.
>> Read the full publication here