Quantifying neutralising antibody responses against SARS-CoV-2 in dried blood spots (DBS) and paired sera
Roper KJ., Thomas J., Albalawi W., Maddocks E., Dobson S., Alshehri A., Barone FG., Baltazar M., Semple MG., Ho A., Turtle L., Donegan C., Spencer RG., Moore SC., Hardwick H., Solomon T., Turtle LCW., da Silva Filipe A., Ho AYW., McDonald SE., Palmarini M., Robertson DL., Scott JT., Thomson EC., Chand M., Tedder RS., Price N., Leeming G., Bogaert D., Russell CD., Docherty AB., Drake TM., Fairfield CJ., Harrison EM., Knight SR., Mclean KA., Murphy D., Norman L., Pius R., Shaw CA., Horby PW., Swann OV., Chechi K., Thompson AAR., Cooke GS., Sriskandan S., Summers C., Greenhalf W., Sancho-Shimizu V., Khoo S., Noursadeghi M., Stuart D., Norris L., Gupta RK., Rambaut A., Green CA., Shaw V., Keating S., Carson G., Merson L., Sigfrid L., Lee J., Plotkin D., Connor M., Dalton J., Donohue C., Gamble C., Girvan M., Halpin S., Harrison J., Jackson C., Marsh L., Roberts S., Saviciute E., Fletcher T., Palmieri C., Meynert AM., Wham M., Openshaw PJM., Thwaites RS., Dunning J., Zambon M., dos Santos Correia G., Lewis MR., Maslen L., Sands CJ., Takis P., Lim WS., Mentzer AJ., Klenerman P., Grammatikopoulos T., Knight S., Tait S., Baillie JK., Clohisey S., Griffiths F., Hendry R., Law A., Oosthuyzen W., Alex B.
The ongoing SARS-CoV-2 pandemic was initially managed by non-pharmaceutical interventions such as diagnostic testing, isolation of positive cases, physical distancing and lockdowns. The advent of vaccines has provided crucial protection against SARS-CoV-2. Neutralising antibody (nAb) responses are a key correlate of protection, and therefore measuring nAb responses is essential for monitoring vaccine efficacy. Fingerstick dried blood spots (DBS) are ideal for use in large-scale sero-surveillance because they are inexpensive, offer the option of self-collection and can be transported and stored at ambient temperatures. Such advantages also make DBS appealing to use in resource-limited settings and in potential future pandemics. In this study, nAb responses in sera, venous blood and fingerstick blood stored on filter paper were measured. Samples were collected from SARS-CoV-2 acutely infected individuals, SARS-CoV-2 convalescent individuals and SARS-CoV-2 vaccinated individuals. Good agreement was observed between the nAb responses measured in eluted DBS and paired sera. Stability of nAb responses was also observed in sera stored on filter paper at room temperature for 28 days. Overall, this study provides support for the use of filter paper as a viable sample collection method to study nAb responses.