Coronavirus: The impact on other vaccination programmes

The Covid-19 outbreak has challenged health services in countries around the world. It has also dominated the time of international agencies such as the World Health Organisation (WHO) and the United Nations (UN). This has led to concern about other global health areas being neglected; for example, the delivery of vaccination and immunisation programmes in developing countries.

As of 13 April, the UN estimated that significant elements of immunisation programmes in 24 countries had been delayed due to Covid-19. Programmes in a further 13 countries were set to be cancelled altogether. This article will examine the extent of the issue, and what the WHO and the UN have recommended in response.

Why are immunisation programmes being delayed and cancelled?

Countries with active vaccination programmes face a difficult balancing act between dealing with the current Covid-19 pandemic and maintaining immunisation levels against vaccine preventable diseases (VPDs). Seth Berkley, the head of Gavi, the Vaccine Alliance, has described the dilemma as “a devil’s choice”. Reasons given for this include:

  • the Covid-19-related burden on health systems diverting staff and resources away from existing immunisation programmes;
  • the large gatherings of people required for mass vaccination campaigns are no longer feasible;
  • a decreased demand and a decline in uptake of vaccinations due to social distancing policies;
  • the economic impact on households causing instability and abnormal health behaviour; and
  • restrictions on travel leading to difficulties in supply for essential medicines and vaccines.  

Why is it important that immunisation programmes continue?

The UN has stated that immunisation against VPDs is a core health service that “should be prioritised during the Covid-19 pandemic, where feasible”.

Disruption to the delivery of vaccinations for VPDs, such as measles, polio, diphtheria, cholera and yellow fever, could lead to a decline in immunity levels in a population, and therefore make an outbreak more likely. This is a particular concern for young infants and children in poorer countries.

Failure to maintain immunisation programmes could also lead to a dangerous convergence of diseases. Research has shown that, during the 2014 and 2015 Ebola outbreak in West Africa, more people died of measles and other conditions attributed to wider health system failure than from the Ebola virus itself.

Measles

Concern has been raised about maintaining delivery of measles vaccinations. Reasons for this include:

  • measles is extremely contagious, with a basic reproduction number (R number) of 12–18, meaning that a new case of measles in a population where everyone is susceptible would infect a further 12–18 people;  
  • a high level of immunity in a population is required to prevent outbreaks; and
  • there are existing difficulties for poorer countries in launching the second dose of the measles vaccine, recommended for full immunity.

In comparison to measles, the estimated averages for the R number of Covid-19 have been around 2.6.

Cases of measles were increasing before the Covid-19 pandemic. Global cases in 2018 had increased 58% since 2016. This was believed to be partly due to an increase of cases in richer countries caused by vaccine hesitancy. In poorer countries, however, it is more likely to be caused by difficulties in delivering the vaccine itself.

Measles remains a deadly disease, with more than 140,000 deaths in 2018 alone, with most of these being children under the age of five. The vast majority of measles deaths occur in poorer countries with weak health infrastructures.  

The Measles and Rubella Initiative, a global partnership with members including the UN, the American Red Cross and the WHO, estimated that, as of 13 April, more than 117 million children were at risk of missing out on the measles vaccine as a result of Covid-19.

In the UK, there has been concern about children missing measles vaccinations as a result of parents keeping them at home due to Covid-19 fears.

What is the recommended course of action?

On 26 March, the WHO published guidance for immunisation activities during the Covid-19 pandemic.

It called for the temporary suspension of mass vaccination campaigns. Programmes where routine vaccination at clinics could continue with physical distancing measures in place should continue. The WHO acknowledged that this will depend on the capacity of individual health systems. It stated:

Immunisation is a core health service that should be prioritized for the prevention of communicable diseases and safeguarded for continuity during the Covid-19 pandemic, where feasible.

The WHO also recommended that if a delay or a cancellation in immunisation programmes was necessary, countries would “need to design strategies for catch-up vaccination for the period post Covid-19 outbreak”. This should include:

  • tracking and following-up with individuals who missed vaccinations;
  • assessing immunity gaps; and
  • re-establishing community demand.

UNICEF have called for these measures to prioritise children, particularly those in poorer countries.

Public health experts have cited the Ebola outbreak in West Africa during 2014 and 2015 as a positive example of these recommended measures. The campaigns to re-establish and strengthen routine immunisation in the wake of that outbreak were largely successful, with coverage post-outbreak actually exceeding previous levels. However, the Ebola outbreak was mainly confined to three countries; the challenge posed by Covid-19 is global, and therefore presents a much greater threat to successful immunisation again VPDs.

Read more

Image by Katja Fuhlert from Pixabay.