‘Urgent’ need for Strep B vaccine to prevent baby deaths

The World Health Organization (WHO) has called for urgent development of vaccines against Group B streptococcus, also known as GBS or Strep B, as new figures reveal that the bacterium is responsible for 150,000 deaths ofbabiesworldwide each year.

The report by the WHO and the London School of Hygiene and Tropical Medicine (LSHTM) says the bacterium, which is harmless for most pregnant women who carry it, is linked to 46,000 stillbirths annually and more than half a million preterm deliveries. It can also cause long-term disability.

Several vaccine candidates are currently under development but none are yet available despite having been in the pipeline for decades, according to the WHO.

“Developing countries bear the highest burden of Strep B, which kills almost 200,000 babies each year, report shows.”

Joachim Osur, Vice Chancellor, Amref International University, Nairobi

Healthexperts say a maternal vaccine against GBS could be highly cost-effective and benefit all regions of the world, particularly low- and middle-income countries (LMICs) where the vast majority of cases occur.

“这项新的研究首次量化了GBS对术前出生以及神经系统障碍的主要贡献，例如脑瘫，听力和视力丧失，这可能会在GBS相关感染后发生，”医疗菲利普·兰巴赫（Philipp Lambach）说。”officer with the WHO’s vaccines and biologicals department who co-authored the study.

He said the research showed that Strep B is a major and unappreciated threat to newborn survival and wellbeing with devastating effects for families worldwide.

LMICs are particularly hard hit, the research shows, accounting for 98 per cent of cases.

Joy Lawn, directorof the Maternal Adolescent Reproductive and Child Health (MARCH) Centre at LSHTM and a contributor to the report, said: “Sub-Saharan Africa has a disproportionate burden, since Africa has 13 per cent of the world’s population and almost five per cent of burden of GBS deaths for newborns and stillbirths.”

Lawn认为，更担心的是，卫生专业人员通常在任何地方和任何地方都会错过GBS案件。她解释说：“世界上大多数助产士都会看到案件，但可能不知道是否没有接受调查。”

According to Joachim Osur, a reproductive health expert and Vice Chancellor at Amref International University in Nairobi, the problem could be even more pronounced in Africa than figures suggest.

“The problem in Africa is that due to weak health systems, we do not investigate causes of intrauterine or foetal deaths. We therefore do not know the causes,” explained Osur.

“This bacterium could be causing many deaths in our communities. The sooner we can get the vaccine, the better.”

该报告称，全世界所有孕妇平均15％（每年几乎为2亿孕妇）在其阴道中携带GBS细菌，通常没有症状。它可以在出生期间或生命早期在子宫中传播给婴儿。

Currently antibiotic treatment given to women during labour are the main means of preventing GBS diseases in newborn infants, the study says.

如果在怀孕期间检测到细菌,怎么做ever, even in regions with high treatment coverage, there remain significant risks as this intervention is unlikely to prevent most GBS associated stillbirths, preterm births or GBS diseases that occur later after birth, it adds.

According to Martina Lukong Baye, coordinator of a national programme to combat maternal, newborn and child mortality at the Ministry of Health in Cameroon, a new maternal vaccine against GBS would be a game-changer in the reduction of newborn and maternal deaths for the most affected countries, especially in Sub-Saharan Africa.

Several vaccines are at phase two clinical trials, said Lambach, adding: “Some of them are multivalent, covering most of the major strains of GBS in pregnant women.”

但是他补充说，疫苗开发是复杂且昂贵的，尤其是在晚期临床试验中，由于证据差距，存在不确定性。

Assumptions about the severity of the disease as well as feasibility of implementation in low-resource settings may also have been preventing manufacturers from prioritising GBS vaccine development.

“The evidence and analysis in the report aim to help assure manufactures, [by] indicating that the disease burden is greater than previously assumed,” Lambach added. “And by suggesting that an affordably-priced vaccine is likely to be cost-effective, have a positive global net monetary benefit … and likely be financially sustainable and profitable if adopted in low-, middle-, and high-income countries.”

This piece was produced by SciDev.Net’s Global desk.