EXCLI J EXCLI Journal 1611-2156 Leibniz Research Centre for Working Environment and Human Factors 2015-607 10.17179/excli2015-607 Doc1133 Letter to the editor ELISA for detection of humoral immunity against measles Zahoor Muhammad Asif * 1 Saqalein Muhammad 1 Nawaz Zeeshan 1 Department of Microbiology, Govt. College University, Faisalabad-Pakistan *To whom correspondence should be addressed: Muhammad Asif Zahoor, Department of Microbiology, Govt. College University, Faisalabad-Pakistan; Tel: 92-41-9201205, E-mail: drasifzahoor@gcuf.edu.pk 20 10 2015 2015 14 1133 1134 01 10 2015 18 10 2015 Copyright © 2015 Zahoor et al. 2015

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Dear Editor,

Measles is a highly infectious and contagious disease of the respiratory system caused by Morbilivirus (Hashiguchi et al., 2011[5]). The clinical disease has been characterized by high fever, cough, conjunctivitis, coryza, malaise, maculopapular rash and erythematous patches throughout the body along with increased mortality among non-vaccinated children (Ellison, 1931[3]; Fazlalipour et al., 2008[4]). Expanded Program on Immunization (EPI) has been launched in 1974 under the umbrella of World Health Organization (WHO) with the ultimate objective of elimination of Vaccine Preventable Diseases (VPDs) in children, further this program was initiated in Pakistan during 1978 (Ali, 2000[1]; Bugvi et al., 2014[2]). Among the VPDs, measles has been considered as one of most important diseases in children throughout the world particularly in developing countries (Rabenau et al., 2007[10]; Liu et al., 2013[7]). Furthermore, vaccination against measles is widespread which significantly reduces the mortality and morbidity across the globe (Perry and Halsey, 2004[9]; Leuridan and Van Damme, 2007[6]). Vaccination with first dose is recommended at the age of 9 months with booster dose at the age of 12 or 15 months with either live attenuated measles virus or Measles-Mumps-Rubella complex (MMR) as described (Leuridan and Van Damme, 2007[6]; Sheikh et al., 2011[11]). The immunization against measles virus usually resulted in protection due to humoral as well as cell mediated immune response (Ovsyannikova et al., 2003[8]). Many immunodiagnostic methods have been used for the detection of anti-measles antibodies as described by Perry and Halsey (2004[9]). Among those, Enzyme Linked Immunosorbent Assay (ELISA) has been reported as more sensitive and specific with reproducibility of results for detection of anti-measles antibodies (Fazlalipour et al., 2008[4]). Further, ELISA for measles has been reported to detect and quantify anti-measles IgG antibodies with high sensitivity and specificity (Rabenau et al., 2007[10]).

Therefore, keeping in view the importance and significance of measles, this preliminary study was designed to develop an ELISA for detection of humoral immunity. For this purpose ELISA plates were coated with measles virus CAM-70 strain (PT Bio Farma, Bandung, Indonesia) which contain not less than 1000 CCID50 in 0.5 ml. Coating of plates was performed using carbonate buffer as described by van der Werff (2008[12]). Briefly, 100 µl of virus diluted with 0.05 M carbonate buffer was added in wells of ELISA plates in duplicate, following overnight incubation at 4 °C, blocking was achieved by adding 300 µl of blocking buffer (PBS + 10 % w/v skimmed milk powder). ELISA was performed as recently described by Zahoor et al. (2015[13]). Briefly, each serum sample was diluted with serum diluent and 100 µL of each diluted serum sample was added in each well of ELISA plate along with controls (Nova Tec Immunodiagnostica GmbH, Germany). Following incubation of ELISA plate for one hour at 37 °C, plate was washed with 300 µl of washing buffer. In the next step, 100 µl measles anti-IgG conjugate (Nova Tec Immunodiagnostica GmbH, Germany) was added into all wells except for the blank well, and kept for 30 minutes at room temperature. Finally, 100 µl tetramethylbenzidine substrate (TMB) was added into all wells, and kept at room temperature for 15 minutes in dark. Reaction was stopped by using 100 µl of stop solution into all wells. Absorbance of the ELISA plate was determined at 450 nm within 30 minutes after addition of the stop solution (Biotek®, ELX 808, USA). Altogether, it was concluded that the developed ELISA may be used to detect humoral immunity from vaccinated children to evaluate the effectiveness of measles vaccination following further standardization and optimization of developed ELISA protocol.

Conflict of interest

The authors declare that they have no conflict of interest.

Ali SZ Health for all in Pakistan: achievements, strategies and challenges East Med Health J 2000 6 832 837 Bugvi AS Rahat R Zakar R Zakar MZ Fischer F Nasrullah M Factors associated with non-utilization of child immunization in Pakistan: evidence from the demographic and health survey 2006-07 BMC Public Health 2013 14 232 Ellison JB Pneumonia in measles Arch Dis Child 1931 6 37–52 Fazlalipour M Monavari SH Shamsi SM Ataei A Evaluation of immune status to measles in vaccinated population in Tehran, by enzyme-linked immunosorbent assay and the hemagglutination inhibition techniques (1386-1387) Iran J Virol 2008 2 27 30 Hashiguchi T Maenaka K Yanagi Y Measles virus hemagglutinin: structural insights into cell entry and measles vaccine Front Microbiol 2011 2:247 1 7 Leuridan E Van Damme P Passive transmission and persistence of naturally acquired or vaccine-induced maternal antibodies against measles in newborns Vaccine 2007 25 6296 6304 Liu Y Lu P Hu Y Wang Z Deng X Ma F Cross-sectional surveys of measles antibodies in the jiangsu province of china from 2008 to 2010: the effect of high coverage with two doses of measles vaccine among children PLoS ONE 2013 8 6 e66771 Ovsyannikova IG Dhiman N Jacobson RM Vierkant RA Poland GA Frequency of measles virus-specific CD4+ and CD8+ T cells in subjects seronegative or highly seropositive for measles vaccine Clin Diagn Lab Immunol 2003 10 411–6 Perry RT Halsey NA The clinical significance of measles: a review J Infect Dis 2004 189 4 16 Rabenau HF Marianov B Allwinn R Comparison of the neutralizing and ELISA antibody titres to measles virus in human sera and in gamma globulin preparations Med Microbiol Immunol 2007 196 151–5 Sheikh S Ali A Zaidi AKM Agha A Khowaja A Allana S Measles susceptibility in children in Karachi, Pakistan Vaccine 2011 29 3419–23 van der Werff N Measles ELISA 2008 Biomedical Primate Research Centre Available from: http://www.malariaresearch.eu/eumalar/sites/sbsweb2.bio.ed.ac.uk.eumalar/files/pdfs/Measles%20ELISA%20-%20BPRC.pdf Zahoor MA Rasool MH Waseem M Aslam B Zahoor MK Saqalein M Prevalence of measles in vaccinated and non-vaccinated children EXCLI J 2015 14 504 507