When should a vaccine be introduced in post-disaster zones?

By Sophie Cousins 25 November 2015

A child receives vaccination at a health clinic in Nepal. When should a vaccine be introduced in post-disaster zones? Photo by: Jim Holmes / DfAT / CC BY

It has been more than six months since the devastating 7.8-magnitude earthquake hit Nepal. More than 9,000 people lost their lives and hundreds of thousands of people were displaced. Numerous health care centers, hospitals and village health posts in the worst-affected areas were destroyed, along with water and sewerage systems.

Months on, thousands still live in makeshift shelters and camps, many with limited access to clean drinking water and toilets. To make matters worse, the monsoon season hit and increased legitimate fears of widespread disease outbreak. Some even suggested it was possible more Nepalese would die of disease than the earthquake itself.

Consequently, a group of eminent international doctors, including Jeremy Farrar, the director of the Wellcome Trust, called for the speedy introduction of a vaccine against hepatitis E infection, which they said could prevent the deaths of more than 400 pregnant women.

But this call was met with fierce doubt over the necessity and safety of the vaccine from other experts.

Hepatitis E, which is spread through contaminated water, is common in Nepal but has largely been confined to Kathmandu Valley. Its highest incidence is in young adults and it’s an important cause of maternal mortality, according to the World Health Organization.

In April 2014 there was an outbreak in east Nepal, which infected more than 6,000 people and left at least 10 dead.

Although a vaccine called HEV239 has been developed, it’s only available in China, and hasn’t been prequalified by the WHO. Prequalification aims to ensure vaccines, medicines and diagnostics for high-burden diseases meet global standards of quality, safety and efficacy.

But while experts agree that prevention is key, many have been divided on the necessity of the introduction of hepatitis E vaccine in post-quake Nepal.

Such an issue raises some interesting questions: When should a vaccine be introduced in post-disaster zones? And what considerations should be taken into account when NGOs and experts decide their stance on the rollout of vaccines post-disaster?

Safety first

WHO representative to Nepal, Dr. Jos Vandelaer, said the organization’s primary consideration was the health and safety of vulnerable populations.

“In assessing the possible benefits of immunization programs in post-disaster contexts, it is important to look at factors such as epidemiological risks, the proven safety of the vaccine, and the vaccine’s efficacy and availability,” she said.

“We must also consider the possibility of vaccination as complementary to a range of other frontline preventative measures such as those related to water, sanitation and hygiene, and the implementation of a robust disease surveillance and rapid response system.”

Hepatologist Dr. Ananta Shresha, who is a specialist on hepatitis E, said international doctors’ concerns about an outbreak were overestimated and that their estimation of 400 pregnant women being at risk of dying was “totally incorrect.”

“Vaccination is not the right way to handle the current situation. The safety of the vaccine hasn’t been established and while hepatitis E is here in the population, there have only been sporadic cases,” he added.

Buddha Basnyat, director of the Oxford University Clinical Research Unit at Patan Hospital in Kathmandu, who was a signatory in a letter in The Lancet that called for the speedy introduction of a hepatitis E vaccination, disagreed.

“The WHO is going to take a long time with prequalification [of hepatitis E vaccination] but I don’t think I would mind if the Chinese gave us the vaccine,” he said. “The government of Nepal can decide to buy the vaccine but the problem is that it’s too poor.”

Public health expert Sameer Dixit, from the Center For Molecular Dynamics, attended a hepatitis E symposium outside Kathmandu earlier this month. He said that at the end of the day, public health experts agreed there was much more to be learned about hepatitis E before rushing to vaccinate people.

“The bottom line is that there has been no outbreak of hepatitis E anywhere after the earthquake,” he said.

“We concluded that while it is a public health problem, there’s still a lot to be learned about the disease. We need the full data to even think about introducing a vaccine.”

Getting prepared

Dr. Vandelaer explained that every government was sovereign in designing and implementing public health policy.

“It is the prerogative of governments to weigh the scientific evidence and WHO’s advice against local circumstances,” she said.

In this respect, the government of Nepal decided to focus on surveillance and the root cause of waterborne diseases: sanitation and access to clean water.

Dixit said it was a miracle Nepal had avoided any mass outbreaks of disease and attributed it to two factors.

“We feel that as soon as the earthquake happened, the epidemiology department really got into preventative mode — there was a rapid response and plans that were practiced before the earthquake were implemented, such as a lot of focus on sanitation and awareness. Pits were also dug for toilets. This had a major impact in rural areas,” he said.

“Secondly, after the earthquake there was meant to be monsoon but the monsoon was less than last year and it hasn’t been as hot as other years. This helped control the spread of disease.”

Another vaccine?

In the wake of the earthquake, many public health experts also called for the introduction of a widespread typhoid vaccination program. The transmission of the bacterial disease is facilitated by poor hygiene and sanitation. And, in the past, Kathmandu has been heralded the typhoid fever capital of the world.

Although the vaccine — the same one recommended by the WHO — was found to be safe and effective in a 1987 clinical trial in the capital city, to this day a mass immunization program against typhoid hasn’t been implemented.

Shresha said he didn’t believe hepatitis E or typhoid vaccination in post-quake Nepal was essential.  

“We can’t vaccinate everyone against a disease. What things should we be looking for in disease that makes vaccination worthwhile? High mortality and morbidity,” he said.

Basnyat said aside from administering the vaccine, it was vital to stockpile it if there was an outbreak.

“Nepal is not known for being proactive, but if there is an outbreak, we need to be better prepared. This is a good opportunity to get the ball rolling.”

He said a major issue was that the recommended WHO typhoid vaccine was too expensive but said there were other vaccines from India that hadn’t been prequalified but were just as effective.

“Yes, prequalification is important because it means UNICEF won’t buy the vaccine for us, but these vaccines are expensive. In Nepal, where vaccines are most needed, who can afford it?”

Prioritizing is key

While Basnyat said school-aged children, who are most vulnerable to typhoid, should be targeted for vaccination, Shresha said it was a waste of resources.

“In the last 10 years I haven’t seen a single person die of typhoid. Why would we use a typhoid vaccination? We should put money toward preventative strategies such as sanitation and clean water. It costs $3.5 to treat someone with typhoid.”

Dr Ashish K.C. from UNICEF’s Nepal health department said the organization has been supporting the government with measles and rubella and tetanus vaccinations since the earthquake in affected areas.

He said he didn’t believe typhoid vaccination was necessary.  

“Typhoid is seasonal — its spikes are similar to the previous year. I don’t think there needs to be a mass campaign,” he said. “I think the most critical vaccinations are measles and rubella and tetanus. We must focus on the diseases with high mortality and morbidity. I think … the best solution is to use preventative measures such as hand-washing and clean water.”

He added that UNICEF couldn’t procure vaccinations for governments that hadn’t been prequalified by the WHO. But as the WHO’s Vandelaer highlighted, if vaccines are implemented, other efforts to control the disease — such as improved sanitation and water quality, along with health education — must be continued.

Dixit stressed that in a country like Nepal, prioritization was key.

“Is it feasible for a country like Nepal to be spending a lot of money on vaccines rather than improving sanitation and other aspects of people’s livelihoods?”

In the end there is no one-size-fits-all approach when responding to a natural disaster. There are myriad factors that need to be considered, but in Nepal’s case, efforts that focused on disease prevention paid off.

With the range of NGOs on the ground, awareness campaigns and the government’s and the WHO’s surveillance system, the country was able to avoid yet another crisis.

To read additional content on global health, go to Focus On: Global Health in partnership with Johnson & Johnson.

About the author

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Sophie Cousins

Sophie Cousins is a health writer based in India. She was previously based between Lebanon and Iraq focusing on refugee health and conflict. She is particularly interested in infectious diseases and rural health in South Asia. She writes for international medical journals, including The Lancet, and for international news websites such as Al-Jazeera English.


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