Bandim Health Project, Bissau, Guinea-Bissau.
Bandim Health Project, Bissau, Guinea-Bissau; OPEN, University of Southern Denmark/Odense University Hospital, Denmark.
Vaccine. 2024 Oct 3;42(23):126056. doi: 10.1016/j.vaccine.2024.06.023. Epub 2024 Jun 12.
The Bacillus Calmette-Guérin (BCG) vaccine is recommended at birth in Guinea-Bissau but often given with delay. Delays are not evident in routine coverage estimates since coverage is measured by 12 months of age. Studies show that BCG protects against other infections than tuberculosis and lowers neonatal mortality. Hence, the timing of BCG is important since the children should benefit from these non-specific effects as early as possible.
Using data from a nationally representative health and demographic surveillance system in Guinea-Bissau, we assessed BCG coverage at birth (within the first 3 days of life), 1 month, and 12 months for children born in 2013-19. We measured the proportion of children who had a documented health system contact within the first 3 days of life, thus an opportunity for BCG at birth, and whether the opportunities were utilized. In binomial regression models, we investigated factors associated with missed opportunities for vaccination.
Among the 22,178 children only 19 % were vaccinated at birth. By 1 month and 12 months, BCG coverages were 64 % and 93 %. The timeliness of BCG improved over time, with coverage at birth increasing from 16 % in 2013 to 25 % in 2019 and 1-month coverage from 63 % in 2013 to 75 % in 2019. If all vaccination opportunities had been utilized, the BCG coverage at birth could have reached 45 % (in the 1-month cohort) instead of the actual coverage of 19 %, as only 40 % of the vaccination opportunities were utilized. Region of residence was associated with having a missed opportunity for vaccination.
The high coverage estimates at 12 months falsely imply that the vaccine is being administered according to the recommended schedule. Our findings suggest that early coverage could be markedly improved by ensuring that children are vaccinated at their first contact with the health system.
卡介苗（BCG）疫苗在几内亚比绍推荐在出生时接种，但通常会延迟接种。由于覆盖范围是通过 12 个月大的年龄来衡量的，因此在常规覆盖估计中并没有明显的延迟。研究表明，BCG 不仅可以预防结核病，还可以降低新生儿死亡率。因此，BCG 的接种时间很重要，因为儿童应该尽早从这些非特异性作用中受益。
利用来自几内亚比绍全国代表性的健康和人口监测系统的数据，我们评估了 2013-19 年出生的儿童在出生时（出生后前 3 天内）、1 个月和 12 个月时的 BCG 接种率。我们测量了在生命的前 3 天内有记录的卫生系统接触的儿童比例，从而评估了在出生时接种 BCG 的机会，以及这些机会是否得到了利用。在二项回归模型中，我们调查了与错过接种机会相关的因素。
在 22178 名儿童中，只有 19%的儿童在出生时接种了疫苗。到 1 个月和 12 个月时，BCG 的覆盖率分别为 64%和 93%。BCG 的及时性随着时间的推移而改善，出生时的覆盖率从 2013 年的 16%增加到 2019 年的 25%，1 个月的覆盖率从 2013 年的 63%增加到 2019 年的 75%。如果所有的接种机会都得到了利用，出生时的 BCG 覆盖率本可以达到 45%（在 1 个月组），而不是实际的 19%，因为只有 40%的接种机会得到了利用。居住地与错过接种机会有关。
12 个月时的高覆盖率估计错误地暗示疫苗是按照建议的时间表接种的。我们的研究结果表明，通过确保儿童在首次接触卫生系统时接种疫苗，可以显著提高早期覆盖率。
